Subject Index

2-chlorophenol (2-CP), 105

2D black phosphorus, 171

2D carbon nanosheets, 163–164

2D carbon nanostructures, 161

• 2D graphene, 161

  • 2D carbon nanosheets, 163–164

  • 2D graphene–metal oxide (MO_x)-based nanotube networks for hybrid supercapacitors, 162–163

  • graphene conducting polymer composites, 162

  • nanotubular networks, 164

• 2D nanomaterial transition metal dichalcogenides, 164

  • 2D metallic TMDs, 165–167

  • 2D TMD/carbonaceous material hybrids, 164–165

  • 2D transition metal oxide and hydroxide electrodes, 167–168

  • TMD/conductive polymer hybrids, 165

2D graphene, 161

• 2D carbon nanosheets, 163–164

• graphene conducting polymer composites, 162

• metal oxide-based nanotube networks for hybrid supercapacitors, 162–163

• nanotubular networks, 164

2D materials

• in organic solar cells, 218–220

• in perovskite solar cells, 220–221

2D metal carbides, 210

2D MXene, 169–170

2D nanocomposites

• for efficient energy conversion, 188

  • black phosphorus-based nanocomposites, 193–194

  • graphitic carbon nitride-based nanocomposites, 190–193

  • metal–organic framework-based 2D nanomaterials, 196–197

  • MXene-based nanocomposites, 194–196

• electrocatalytic hydrogen gas evolution performance of, 190

2D nanomaterial composites

• for batteries, 147

  • aqueous multivalent metal–ion batteries, 152–158

  • monovalent metal–ion batteries, 147–152

• for supercapacitor applications, 158

  • 2D black phosphorus, 171

  • 2D carbon nanostructures, 161–164

  • 2D nanomaterial transition metal dichalcogenides, 164–168

  • 2D transition metal nitrides, 170–171

  • with MXene/2D composite film electrodes, 168–170

• via cost-effective and eco-friendly chemical routes, 141

  • bottom-up approaches, 143–145

  • rational design of 2D nanomaterial composites, 145–146

  • top-down methods, 142–143

2D nanosheets (NSs), 160

2D photocatalysts, 70, 88

2D quantum spin Hall (QSH) insulator, 127

2D transition metal hydroxides, 168

2D transition metal nitrides, 170–171

2D transition metal oxides, 167–168

2-iodoacetamide, 298

3D aerogels, 119

4-tert-butylpyridine (TBP), 227

AAIBs. See aqueous aluminium-ion batteries (AAIBs)

absorbed photon-to-current efficiency (APCE), 89

absorption coefficient, 93

acceptors, 206

activated carbons, 236

adsorbate evolution mechanism (AEM), 39

adsorption, 236, 291

AEM. See adsorbate evolution mechanism (AEM)

aerogels, 120, 122

AFM. See atomic force microscopy (AFM)

AIBs. See artificial inorganic batteries (AIBs)

air pollution, 235

ALD. See atomic layer deposition (ALD)

alkali metal-induced phase transition, 124–125

alkali metal-ion batteries, 172

alloying, 131

aluminium oxide (Al₂O₃), 208

ammonia (NH₃) production, 259

• 2D nanomaterial-based electrocatalysts for, 268

• 2D nanomaterial-based photocatalysts for, 267

• 2D nanomaterial-based photoelectrocatalysts for, 272

• electrocatalysis for, 266–272

• photocatalysis for, 261–266

• photoelectrocatalysis for, 272–274

amorphous boron nitride (a-BN), 49

APCE. See absorbed photon-to-current efficiency (APCE)

apparent quantum efficiency (AQE), 92

applied bias photon-to-current efficiency (ABPE), 89

AQE. See apparent quantum efficiency (AQE)

aqueous aluminium-ion batteries (AAIBs), 152

• energy storage systems, 153

• Fe–Co PBA multivoid nanoframe architecture performance for, 152

• inorganic cathode, 153

• material challenges, 153

• tin oxide quantum dots and graphene, 152

aqueous calcium-ion batteries, 157

• boron nitride monolayer, 157

• molybdenum oxide, 157

• organic cathode, 157–158

aqueous magnesium-ion batteries, 156

• germanium anode, 156

• synergy effect of hydrated ionic radius and oxidation state, 157

• vanadium oxide, 156–157

aqueous multivalent metal-ion batteries, 152

• aqueous aluminium-ion batteries, 152–153

• aqueous calcium-ion batteries, 157–158

• aqueous magnesium-ion batteries, 156–157

• aqueous zinc-ion batteries, 153–156

aqueous zinc-ion batteries (AZIBs), 153

• bilayered Ca_0.26V₂O₅H₂O and NVO@MXene electrode, 156

• combination of 1T-MoS₂ with ammonium vanadate, 153

• galvanostatic intermittent titration technique, 156

• MWCNTs@a-C@MoS₂ cathode for, 156

• oxygen-deficient ammonium vanadate/GO composites, 153

Argand depiction, 81

artificial inorganic batteries (AIBs), 153

asymmetric supercapacitor (ASC), 167

atomic force microscopy (AFM), 72

atomic layer deposition (ALD), 11

atrazine (ATZ), 111

AZIBs. See aqueous zinc-ion batteries (AZIBs)

ball milling, 142, 282, 294

band gap energy, 93–94

batteries, 69, 75, 147, 285

• aqueous multivalent metal-ion batteries, 152–158

• monovalent metal-ion batteries, 147–152

BCPs. See block copolymers (BCPs)

BET surface area. See Brunauer–Emmett–Teller (BET) surface area

biodegradable polymers, 142

bisphenol A (BPA), 105

black phosphorus (BP), 114, 210, 291

block copolymers (BCPs), 143

Bode plot, 81, 82

Boltzmann constant, 85, 87

boron nitride (BN), 49

bottom-up approach, 4, 143, 295

• chemical vapour deposition, 143–144

• hard and soft templating techniques, 144–145

• reverse micelle methods, 145

• sol–gel method, 144

• solvothermal and hydrothermal methods, 144

bottom-up synthesis, 34

• chemical vapor deposition, 35

• plasma-enhanced pulsed laser deposition, 35–36

• spray coating, 36

• urea glass method, 34–35

BP. See black phosphorus (BP)

BPA. See bisphenol A (BPA)

Brunauer–Emmett–Teller (BET) surface area, 11, 72, 249

bulk heterojunction (BHJ) solar cells, 204

Butler–Volmer equation, 83

caesium, 207

calcination, 144

calcium-ion batteries (CIBs), 157

carbide-derived carbons (CDCs), 33

carbon-based materials, 196, 204

carbon capture and storage (CCS), 237

carbon dioxide (CO₂), 235–236, 293

carbon dioxide reduction reaction (CO₂RR), 288

carbon nanotubes (CNTs), 108, 239

carbon nitride (CN), 9, 248

carbon quantum dots, 225

carrier lifetime, 71–72

catalysis, 53

catalysts, 183, 292

cathode interfacial layer (CIL), 212

CB. See conduction band (CB)

CCS. See carbon capture and storage (CCS)

charge carriers, 73

chemical composition, 298

chemical exfoliation, 5–6, 146

chemical oxygen demand (COD), 108

chemical vapor deposition (CVD), 2, 6, 35, 143–144, 217, 295

chronoamperometry, 74

CIBs. See calcium-ion batteries (CIBs)

Clausius–Clapeyron equation, 133

CNTs. See carbon nanotubes (CNTs)

coaxial electrospinning, 142

cobalt ferrite (CoF), 169

Cole–Cole plot, 81

conducting polymers, 210

conduction band (CB), 92, 103, 223, 240

conduction band minimum (CBM), 224

conduction band offset (CBO), 87

conductive atomic force microscopy (CAFM), 117

conductive polymers (CPs), 165

Congo red (CR) dye, 108

Coulomb efficiency, 79

counter electrode, 33, 75

cubic boron nitride (c-BN), 49

CV. See cyclic voltammetry (CV)

CVD. See chemical vapor deposition (CVD)

cyclic voltammetry (CV), 69, 75

• capacitance calculation, 77–78

• energy density and power density calculation, 78

degree of exfoliation, 297

density functional theory (DFT), 115, 267, 288

dielectric materials, 52

diffuse reflectance spectrum (DRS), 93

diffusion coefficient, 80

dimethyl sulfoxide (DMSO), 34

dipole–dipole interactions, 293

donor/acceptor barrier, 205

donor polymers, 206

doping, 131, 246

double-layer capacitance, 75

drop-casting method, 205, 217

DRS. See diffuse reflectance spectrum (DRS)

dye-sensitized solar cell (DSSC), 208

dynamic light scattering, 73

ECSA. See electrochemical surface area (ECSA)

EIS. See electrochemical impedance spectroscopy (EIS)

electrocatalysis, 69, 70, 181, 244, 260, 266–272

electrocatalysts, 73, 266

electrochemical cell, 181

electrochemical double-layer capacitors (EDLCs), 75, 158

electrochemical etching method, 33–34

electrochemical impedance spectroscopy (EIS), 69, 80, 105, 193

• exchange current, 84

• Faradaic efficiency, 82

• overpotential, 83

• Tafel plots, 83–84

• turnover frequency, 84–85

electrochemical surface area (ECSA), 72

electrode–electrolyte interface, 83

electron beam-controlled phase transition, 127–130

electron-donating groups (EDGs), 247

electron energy-loss spectroscopy, 74

electronic band structures, 70–71

electron-induced phase transition, 124

• alkali metal-induced phase transition, 124–125

• alloying and doping, 131

• charge transfer-driven phase transition in donor–acceptor heterostructures, 125–127

• chemically triggered phase transformation on 2D materials, 130–131

• electron beam-controlled phase transition, 127–130

• plasma thermoelectro-induced 2H–1T phase transition, 130

electron paramagnetic resonance (ESR) spectroscopy, 73, 267

electrons, 205

electron-transfer coefficient, 83

electron transport layer (ETL), 208, 215

electron-withdrawing groups (EWGs), 247

electrophotocatalysis, 181

electrospinning, 142

electrospraying, 218

energy density, 78

energy storage, 38–39

energy storage systems (ESSs), 153, 158

environmental remediation, 290–294

epitaxial growth, 6–7

epitaxial layer, 6

EQE. See external quantum efficiency (EQE)

equivalent series resistance (ESR), 82

Escherichia coli, 296

ESR. See equivalent series resistance (ESR)

ESR spectroscopy. See electron paramagnetic resonance (ESR) spectroscopy

ESSs. See energy storage systems (ESSs)

etching, 32–33

ethylene glycol (EG), 49

ETL. See electron transport layer (ETL)

exchange current, 84

exfoliation, 44–46

external quantum efficiency (EQE), 89, 91

fabrication technique, 209

face-centred cubic (FCC), 35

Faraday efficiency (FE), 82, 267

Fermi level, 48, 118, 126

fill factor (FF), 86–87, 214, 223

first-order phase transition, 130

fluorine-doped tin oxide (FTO), 205

formamidine, 207

Fourier transform infrared spectroscopy (FTIR), 74

Fowler–Nordheim tunneling theory, 117

Freundlich adsorption isotherms, 291

FTIR. See Fourier transform infrared spectroscopy (FTIR)

galvanostatic charge–discharge (GCD), 69, 78

• Coulomb efficiency, 79

• energy density and power density calculation, 79

galvanostatic intermittent titration technique, 156

gas-sensing layer, 122

gastrointestinal tract, 295

GCD. See galvanostatic charge–discharge (GCD)

gel, 144

geometric surface area (GSA), 72

germanium anode, 156

GHGs. See greenhouse gases (GHGs)

Gibbs free energy, 90, 132, 187, 193, 269

GO. See graphene oxide (GO)

gold nanoparticles (Au NPs), 130

GQDs. See graphene quantum dots (GQDs)

graphene, 2, 53, 108, 169, 210, 225, 226, 227, 244, 250, 287, 291

• properties of, 4

• synthesis of, 4

  • chemical exfoliation, 5–6

  • chemical vapor deposition, 6

  • epitaxial growth, 6–7

  • liquid-phase exfoliation, 5

  • mechanical exfoliation, 5

graphene-based hybrid photocatalysts, 105–106

graphene-based nanomaterials

• CO₂ capture and conversion, 236–238

• graphene-based 2D material for CO₂ capture and conversion, 244

  • graphene doped with heteroatoms, 245–247

  • metal oxide graphene composite, 248–250

  • MOF–graphene composites, 250–252

  • quantum dot graphene composites, 247–248

• multidimensional materials, 238–239

• role of nanomaterials and their photocatalytic and photoelectrocatalytic applications, 239

  • photocatalytic CO₂ reduction, 241–243

  • photoelectrocatalysis, 243–244

graphene-intercalated compounds (GICs), 6

graphene oxide (GO), 2, 6, 7, 105, 210, 244, 249

• properties of, 8

  • electric properties, 8

  • mechanical properties, 8

  • thermal properties, 8–9

• synthesis of, 9

graphene quantum dots (GQDs), 245, 247

graphitic carbon nitride (g-C₃N₄), 2, 9, 102, 191

• based hybrid photocatalysts, 106

• preparation of, 10

  • exfoliation of bulk g-C₃N₄, 11

  • hard- and soft-template method, 10–11

  • template-free method, 11

• properties of, 9–10

green ammonia, 92

greenhouse gases (GHGs), 237

GSA. See geometric surface area (GSA)

Haber–Bosch process, 92, 237, 260, 274

hard and soft templating techniques, 144–145

h-BN. See hexagonal boron nitride (h-BN)

Helmholtz–Perkin layer, 77

HER. See hydrogen evolution reaction (HER)

heterogeneous catalysis, 190, 260

heterogeneous photocatalysis, 187

hexagonal boron nitride (h-BN), 2, 49, 53, 114, 210, 280

• applications of, 51

  • catalysis, 53

  • dielectric material, 52

  • protecting and passivating layer, 52

  • sensors, 52–53

  • substrates for graphene electronics, 51–52

  • tunnelling barrier, 52

• electronic properties, 51

• mechanical properties, 51

• structure of, 50–51

• synthesis methods of, 53

• thermal properties, 51

high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), 42

highest occupied molecular orbital (HOMO), 205

hole transport layer (HTL), 208, 215

HOMO. See highest occupied molecular orbital (HOMO)

HOR. See hydrogen oxidation reaction (HOR)

hot electrons (HEs), 223

Hummers’ method, 8

hydrogen, 288

hydrogen evolution reaction (HER), 68, 123, 181–184, 288

hydrogen oxidation reaction (HOR), 182, 184

hydrothermal methods, 46, 144, 268

hydrothermal route, 46–48

incident photon-to-current efficiency (IPCE), 89

indium-doped tin oxide (ITO), 117, 205

indophenol blue method, 271

inorganic cathode, 153

in situ characterization techniques, 299

in situ epitaxial growth method, 195

in situ hydrothermal method, 107

intercalation, 34

internal quantum efficiency (IQE), 89

ion-intercalated exfoliation technique, 45

IQE. See internal quantum efficiency (IQE)

Kubelka and Munk (K–M) model, 94

Langmuir–Blodgett assembly, 212

Langmuir–Blodgett technique, 218

large-size graphene oxide (l-GO), 296

laser ablation, 143

lattice oxygen evolution mechanism (LOEM), 39

layer-dependent bandgap engineering, 114–117

layered double hydroxides (LDHs), 102, 170, 263

light-emitting diodes, 4

light-harvesting properties, 70

linear sweep voltammetry (LSV), 273

liquid-phase exfoliation (LPE), 4, 5, 282, 294, 299

lithium bis(trifluoromethane) sulfonimide (Li-TFSI), 227

lithium-ion batteries (LIBs), 38, 48

lithography, 142–143

LOEM. See lattice oxygen evolution mechanism (LOEM)

lowest unoccupied molecular orbital (LUMO), 205

LSV. See linear sweep voltammetry (LSV)

LUMO. See lowest unoccupied molecular orbital (LUMO)

MA. See methylammonium (MA)

manganese dioxide (MnO₂), 41, 167

mass transport process, 73

MBenes, 287, 288

mechanical exfoliation, 5, 34, 146

membrane filtration, 290

mesoporous graphitic carbon nitride (m-gCN), 194

metal alkoxides, 144

metal-assisted chemical etching method, 272

metal clusters, 196

metal-ion batteries, 40

metal nitrides (MNs), 161

metal–organic frameworks (MOFs), 2, 102, 196, 236

• graphene composites, 250–252

metal oxide graphene composite, 248–250

metal sulfide-based hybrid semiconductors, 106–107

metal sulfides, 37

methylammonium (MA), 207, 226

methylammonium lead iodide (CH₃NH₃PbI₃), 208

methylene blue (MB), 109

microwave (MW), 146

microwave-assisted synthesis, 146

MMA-X, 119, 120

MMIBs. See monovalent metal-ion batteries (MMIBs)

mobility, 71–72

MOFs. See metal–organic frameworks (MOFs)

molybdenum disulfide (MoS₂), 52, 214

molybdenum oxide (MoO_x), 157

molybdenum telluride (MoTe₂), 166

monovalent metal-ion batteries (MMIBs), 147

• 2D coordination polymer-derived highly graphitized N-doped carbon nanosheets for effective metal–air batteries, 151

• 2D TMD nanomaterials as cathodes for Li–S batteries, 149

• 2D ZIF-derived ultrathin Cu–N/C nanosheets as high-performance Zn–air battery electrocatalysts, 151–152

• Fe₃Se₄ decorating carbon nanotubes as anodes for SIBs, 149–150

• high-performance anode material for Li/Na-ion batteries using two-dimensional AlB₄, 148

• Li-ion batteries using 2D biphenylene monolayer as anode, 150–151

• MnPSe₃ 2D layer stacking composites as metal-ion battery anodes, 150

• MoS₂–C nanoparticles on two-dimensional graphene sheets as anodes in KIBs, 147

• NiSe nanoparticle-embellished 2D carbon nanosheets as separator modification for high-efficiency LSBs, 149

• two-dimensional carbon-supported MnO@C nanoparticles as anodes in LIBs, 147

• two-dimensional nanosilicon anodes for LIBs, 147–148

• two-dimensional sandwich-like MXene conductive polymer nanocomposite for LSBs, 148

multi-walled carbon nanotubes (MWCNTs), 164

MXene additives, 215–216

MXene aerogel (MA), 120, 121

MXenes, 2, 23, 53, 118, 119, 161, 168, 194, 195, 211, 216, 228, 287, 288, 289

• applications of, 36

  • adsorption of pollutants, 36

  • energy storage, 38–39

  • photocatalytic CO₂ reduction, 38

  • photocatalytic hydrogen evolution reaction, 37–38

• definition of, 23–24

• hexagonal boron nitride, 49

• properties of, 25

  • electronic properties, 25–28

  • magnetic properties, 28–29

  • mechanical properties, 31–32

  • optical properties, 29–30

  • plasmonic properties, 30–31

• structure of, 24–25

• synthesis of, 32

  • bottom-up synthesis, 34–36

  • top-down methods, 32–34

nanomaterials, 141

nanotechnology, 239

nanotubular networks, 164

n-butyl lithium, 297

NDMA. See nitrosamine dimethylamine (NDMA)

Nessler’s reagent method, 263

next-generation lithography (NGL), 143

NGL. See next-generation lithography (NGL)

nitrides, 210

nitrogen oxides (NO_x), 236

nitrogen reduction reaction (NRR), 68, 92, 266, 288

nitrosamine dimethylamine (NDMA), 111

N-methyl-2-pyrrolidone (NMP), 44

non-aqueous solvent, 46

non-Faradaic processes, 75

non-van der Waals layered (NvdW-L) materials, 280, 281, 298, 299

non-van der Waals non-layered (NvdW-NL) materials, 280, 281, 298, 299

NRR. See nitrogen reduction reaction (NRR)

Nyquist plots, 81, 82

OER. See oxygen evolution reaction (OER)

one-pot hydrothermal technique, 195

one-step hydrothermal method, 114

open circuit voltage (OPV), 81, 85–86

open circuit voltage deficit (V_OC-def), 87–88

organic cathode, 157–158

organic linkers, 196

organic materials, 204

organic pollutants, 187, 291

organic solar cells (OSCs), 203, 204, 218–220

• architectures of PSCs, 208–210

• perovskite solar cells, 207–208

• structure of, 205

• types of, 204–206

• working mechanism of, 206–207

ORR. See oxygen reduction reaction (ORR)

oscillatory Belousov–Zhabotinsky reaction, 8

OSCs. See organic solar cells (OSCs)

overpotential, 83

oxidative exfoliation-reduction method, 12

oxygen evolution reaction (OER), 39, 53, 68, 182, 288

oxygen reduction reaction (ORR), 68, 182

• in acidic electrolyte, 185

• in basic electrolyte, 185

PANI. See polyaniline (PANI)

partial density of states (PDOS), 47

partial water dissociation reaction, 188

particulate matter (PM), 236

PDOS. See partial density of states (PDOS)

PEDOT. See poly(3,4-ethylenedioxythiophene) (PEDOT)

PEPLD. See plasma-enhanced pulsed laser deposition (PEPLD)

perovskite solar cells (PSCs), 207–208, 220–221

• architectures of, 208–210

• structure of, 207

photocatalysis, 69, 70, 181, 239, 243, 260, 261–266, 292

• definition of, 186

• porous 2D materials for, 122–124

photocatalysts, 103, 243, 244

photocatalytic CO₂ reduction, 38, 241–243

photocatalytic efficiency, 108

photocatalytic hydrogen evolution reaction, 37–38

photocatalytic process, 186–188

photoelectrocatalysis, 69, 70, 181, 241, 243–244, 260, 272–274

photoelectrochemical cell (PEC), 90, 241

photothermal effect, 195

photovoltaics, 70

piezoelectricity, 283–284

planar n–i–p architecture, 209

Planck’s constant, 93

plasma-enhanced pulsed laser deposition (PEPLD), 35–36

plasma-induced defect engineering, 270

PLD. See pulsed laser deposition (PLD)

PM. See particulate matter (PM)

p–n heterojunctions, 71, 104

polarization voltage, 83

poly(3,4-ethylenedioxythiophene) (PEDOT), 105

poly(vinylidene fluoride-co-hexafluoropropylene), 9

polyaniline (PANI), 8, 105, 161

polydimethylsiloxane (PDMS), 115

polypyrrole (PPy), 105, 161

polythiophene (PTh), 105, 161

polytriphenylamine (PTPAn), 157

polyurethane (PU), 8

polyvinyl alcohol (PVA), 8

porosity, 72–73

Portland cement, 294

power conversion efficiency (PCE), 87

power density calculation, 78

PPy. See polypyrrole (PPy)

pseudocapacitors, 77, 158

PTh. See polythiophene (PTh)

pulsed laser deposition (PLD), 2, 35

PVA. See polyvinyl alcohol (PVA)

QDs. See quantum dots (QDs)

quantum dot graphene composites, 247–248

quantum dots (QDs), 192

quantum wells, 223

Raman spectroscopy, 74, 115, 124

ranitidine (RAN), 111

rational design of 2D nanomaterial composites, 145

• mechanical and chemical exfoliation, 146

• microwave-assisted synthesis, 146

• via cost-effective chemical routes, 146

• via eco-friendly chemical routes, 146

reduced graphene oxide (rGO), 2, 7, 105, 152, 212, 245, 296

• properties of, 8

  • electric properties, 8

  • mechanical properties, 8

  • thermal properties, 8–9

• synthesis of, 9

reference electrode, 75

Ren method, 39

restacking, 74

reverse micelle methods, 145

reversible hydrogen electrode (RHE), 267

rGO. See reduced graphene oxide (rGO)

rhodamine B (RhB), 108

ruthenium-based materials, 260

scalability, 282

scanning electron microscopy (SEM), 72, 262

scanning transmission electron microscopy (STEM), 127

Schottky barrier, 113

Schottky junctions, 38, 71, 104

Scotch tape method, 69, 146, 282

SCs. See supercapacitors (SCs)

self-agglomeration, 74

self-assembly, 48–49

SEM. See scanning electron microscopy (SEM)

semiconductor-based nanocatalysts, 181

semiconductor materials, 114

sensors, 52–53

series resistance (R_s), 87

Shockley–Reid–Hall (SRH) recombination, 86

short circuit current (I_SC), 86, 214, 223

SIBs. See sodium-ion batteries (SIBs)

silicon carbide (SiC), 6

sluggish process, 39

small-angle neutron scattering, 73

small-angle X-ray scattering, 73

small-size graphene oxide (s-GO), 296

SMT. See sulfamethazine (SMT)

SMX. See sulfamethoxazole (SMX)

sodium-ion batteries (SIBs), 39

solar cells, 4, 118, 203

solar spectrum, 107

sol–gel method, 144

solvothermal methods, 144, 210

solvothermal treatment, 265

specific surface area (SSA), 72

spin-coating method, 205, 217

spin–valley coupling (SVC), 18

SPM. See surface probe microscopy (SPM)

SPR. See surface plasmon resonance (SPR)

spray coating technique, 36, 213, 217

sputtering process, 143, 213

SSA. See specific surface area (SSA)

S-scheme, 104, 192

steam-reforming process, 260

STEM. See scanning transmission electron microscopy (STEM)

strain-induced phase transition, 132–134

successive ionic layer adsorption and reaction (SILAR), 192

sulfamethazine (SMT), 111

sulfamethoxazole (SMX), 111

sulfur dioxide (SO₂), 236

supercapacitors (SCs), 68, 169, 172, 245, 287

• applications, 158

  • 2D black phosphorus, 171

  • 2D carbon nanostructures, 161–164

  • 2D nanomaterial transition metal dichalcogenides, 164–168

  • 2D transition metal nitrides, 170–171

  • with MXene/2D composite film electrodes, 168–170

surface functionalization, 296, 298

surface modification, 213

surface plasmon resonance (SPR), 113

surface probe microscopy (SPM), 117

SVC. See spin–valley coupling (SVC)

synthesis routes, 44

• exfoliation, 44–46

• hydrothermal route, 46–48

• self-assembly, 48–49

Tafel plots, 83–84

Tafel reaction, 183

Tafel slope, 84

tantalum carbide (TaC), 35

Tauc–Kubelka–Munk relationship, 94

TC. See tetracycline (TC)

TEM. See transmission electron microscopy (TEM)

template-free method, 11

Terminalia arjuna, 105

tert-butyl lithium, 297

tetraalkylammonium hydroxides, 34

tetracycline (TC), 109, 111

tetramethylammonium hydroxide (TMAH), 46

thermal resistance, 236

thiamethoxam (TM), 108

three-dimensional (3D) materials, 2

three-dimensional (3D) metal–organic frameworks, 236

time-resolved photoluminescence spectroscopy (TPRL), 73

tin oxide quantum dots (SnO₂ QDs), 152

titanium dioxide (TiO₂), 41, 241

TMAH. See tetramethylammonium hydroxide (TMAH)

TMDs. See transition metal dichalcogenides (TMDs)

TMOs. See transition metal oxides (TMOs)

top-down approach, 4, 7, 9, 32, 142, 294–295

• ball milling, 142

• electrochemical etching, 33–34

• electrospinning, 142

• etching, 32–33

• intercalation, 34

• laser ablation, 143

• lithography, 142–143

• mechanical exfoliation, 34

• sputtering, 143

total organic carbon (TOC), 105

transition metal dichalcogenides (TMDs), 2, 12, 39, 53, 102, 161, 169–170, 210, 211, 214–215, 280, 287

• correlation between monolayer count and band structure of, 17–20

• electronic structure and properties of, 15–17

• general and current development in synthesis of, 21–23

transition metal nitrides (TMNs), 170

transition metal oxides (TMOs), 2, 53, 193, 288

transmission electron microscopy (TEM), 72, 109, 262

transparent conducting oxide (TCO), 205

transparent conductive electrodes (TCE), 210

triazine, 191

tri-s-triazine, 191

Triton X-100, 11

tungsten carbide (WC), 35

tunnelling barrier, 52

turnover frequency (TOF), 84–85

two-dimensional MgB₂, 289

two-dimensional (2D) nanomaterials, 1, 69, 103, 181, 197, 238, 252, 279

• 2D nanocomposites for efficient energy conversion, 188

  • black phosphorus-based nanocomposites, 193–194

  • graphitic carbon nitride-based nanocomposites, 190–193

  • metal–organic framework-based 2D nanomaterials, 196–197

  • MXene-based nanocomposites, 194–196

• bandgap engineering of 2D semiconductor materials, 114

  • layer-dependent bandgap engineering, 114–117

  • solar-to-chemical energy conversion by, 117–118

• basics and scalable synthesis methods, 280

  • synthesis methods, 281–283

• biocompatibility of, 280

• as charge transport layers, 211

  • graphene and derivatives, 211–214

  • MXene additives, 215–216

  • transition metal dichalcogenides, 214–215

• composites as ETL in perovskite solar cells, 221–226

• composites as HTL in perovskite solar cells, 226–228

• as electrocatalysts, photocatalysts, and photoelectrocatalysts, 70

  • abundant surface active sites, 73

  • alleviated restacking, 74

  • carrier lifetime and mobility, 71–72

  • electronic band structures, 70–71

  • excellent electronic conductivity, 73

  • high electrochemically active surface area, 72

  • kinetics of ions/charge carriers, 73

  • light-harvesting properties, 70

  • porosity, 72–73

  • stability, 74

• electrochemical profile evaluation, 75

  • cyclic voltammetry, 75–78

  • electrochemical impedance spectroscopy, 80–85

  • galvanostatic charge–discharge, 78–79

• energy and environmental prospectives, 283

  • energy applications, 283–290

  • environmental remediation, 290–294

• environmental impact of, 295–298

• environmental impact of synthesis processes of, 294

  • bottom-up approaches, 295

  • top-down approaches, 294–295

• fundamental electro-, photoelectro-, and photocatalytic energy applications, 181

  • mechanism of HER, 183–184

  • mechanism of HOR, 184

  • mechanism of OER, 186

  • mechanism of ORR, 185–186

  • photocatalytic process, 186–188

• graphene, 2–7

• graphene oxide and reduced graphene oxide, 7–9

• graphitic carbon nitride, 9

  • conclusion for, 11–12

  • preparation of, 10–11

  • properties of, 9–10

• hexagonal boron nitride, 49

  • applications of, 51–53

  • properties of, 51

  • structure of, 50–51

  • synthesis methods of, 53

• hybridization of 2D semiconductor nanomaterials with other nanomaterials, 103

  • graphene-based hybrid photocatalysts, 105–106

  • graphitic carbon nitride-based hybrid photocatalysts, 106

  • hybridization with inorganic semiconductors, 111–113

  • hybridization with metals, 113–114

  • metal–organic framework-based hybrid semiconductors, 111

  • metal sulfide-based hybrid semiconductors, 106–107

  • MoS₂-based hybrid semiconductors, 107–110

• key photovoltaic parameters, 85

  • fill factor, 86–87

  • open circuit voltage, 85–86

  • open circuit voltage deficit, 87–88

  • power conversion efficiency, 87

  • series resistance, 87

  • short circuit current, 86

• MXenes, 23

  • applications of, 36–39

  • definition of, 23–24

  • properties of, 25–32

  • structure of, 24–25

  • synthesis of, 32–36

• in organic solar cells, 218–220

• in perovskite solar cells, 220–221

• photochemical profile evaluation, 88

  • calculation of band gap energy, 93–94

  • definitions of different photocatalytic efficiencies, 89

  • solar energy to ammonia conversion efficiency, 92

  • solar to hydrogen efficiency, 89–91

• photoelectrochemical profile evaluation, 94

• structural engineering of 2D semiconductor nanomaterials, 118

  • electron-induced phase transition, 124–131

  • heterostructure formation to make 3D structure, 118–122

  • phase transition in 2D materials, 124

  • porous 2D materials for photocatalysis, 122–124

  • strain-induced phase transition, 132–134

• transition metal dichalcogenides, 12

  • correlation between monolayer count and band structure of, 17–20

  • electronic structure and properties of, 15–17

  • general and current development in synthesis of, 21–23

• transition metal oxides, 39

  • crystal structure of 2D layered TMOs, 41–42

  • optical and electronic properties of, 42–44

  • synthesis routes, 44–49

type I heterojunctions, 71, 104

type II heterojunctions, 71, 104

type III heterojunctions, 71, 104

ultrasonic exfoliation method, 214

ultrasound, 45

urea glass method, 34–35

valence band (VB), 92, 103, 223, 240

vanadium oxide (VO_x), 156–157

van der Waals (vdW) forces, 2, 3, 74

van der Waals layered (vdW-L) materials, 280

VB. See valence band (VB)

volatile organic compounds (VOCs), 106, 236, 293

Volmer–Heyrovsky mechanism, 183

Volmer step, 183

Volmer–Tafel mechanism, 183

voltammogram trace, 75

water electrolysis systems, 69

water splitting reaction, 188

Watt–Chrisp method, 265, 271

wet milling, 282

working electrode, 33, 75

wurtzite boron nitride (w-BN), 49

XBenes, 288, 294

Xie’s method, 39

XPS. See X-ray photoelectron spectroscopy (XPS)

X-ray diffraction (XRD),192, 265

X-ray photoelectron spectroscopy (XPS), 72–73

XRD. See X-ray diffraction (XRD)

zeolites, 236

zero-bandgap material, 4

Z-schemes, 71, 104, 108, 192