Preface

Graphene, a two-dimensional (2D) monolayer of sp²-hybridized carbon tightly bonded in a hexagonal lattice, is the basic building block for all graphitic carbons. Along the starlight avenue of carbon materials including zero-dimensional (0D) fullerenes, one-dimensional (1D) carbon nanotubes (CNTs), and three-dimensional (3D) graphite, two-dimensional graphene has become an important material for various applications.

As a rising star, the great progress on the functionalization of graphene into chemically derived graphene-related materials in the last few years, including the synthesis and understanding of fundamental properties, has significantly boosted the exploration of promising applications. This book aims to summarize recent research advances on the design and exploitation of chemically derived graphene (CDG) materials for various potential applications. Beginning with a brief description of the basic properties of graphene, particular focus is set on the functionalization of graphene-based materials as active materials for energy conversion and storage and environmental applications, given the large inherent potential of such materials to maximize their performance.

In Chapter 1, an overall introduction on CDG, from preparation methods to properties, is presented. Some challenges with respect to the technology, economics, and environment in the graphene industry are also given to guide its development in the future. Following in Chapter 2 is the introduction of edge-selective functionalization of graphene nanoplatelets (GnPs) using Friedel–Crafts acylation and mechanochemical reactions. The selective functionalization at the edges allows the tunability of the properties of GnPs for specific applications, from polymer composites and flame retardants to energy conversion and storage systems.

With the global energy consumption increasing at an alarming rate, the development of clean and renewable energy conversion techniques has become even more critical. Chapter 3 addresses the functionalization of CDG as electrocatalytic materials for the conversion of chemical energy into electrical energy in proton-exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). The functionalization of CDG with a photoactive material (e.g., semiconductors) or, less commonly, the self-functionalization of CDG is essential for the design of solar specialized graphene-based materials. Chapter 4 reveals the versatility of functionalization to make fascinating graphene-based materials for solar energy conversion. Furthermore, the latest developments of graphene-based composites with improved photocatalytic properties are summarized in Chapter 5. The fundamental roles of CDG in photoactive applications, with emphasis on the performance enhancement, are discussed. Future research, perspectives, and challenges are also outlined in the above chapters.

For electrochemical energy storage, Chapter 6 provides an overview of the significant progress achieved on CDG-based electrodes for lithium- and sodium-ion batteries. In addition to the impressive electrochemical performance reported, emerging challenges and perspectives on the application of graphene-based electrodes are also presented in this chapter. Metal (e.g., Li, Na, Zn, Al)–air batteries are viewed as promising energy devices. Chapter 7 discusses the application of CDG as electrode materials for these metal–air batteries, with a special focus on the development of graphene-based electrodes in Li–air batteries. Chapter 8 summarizes the work on CDG-based materials used as components of lithium–sulfur batteries. To improve the performance, functionalized graphene materials have been used as additives in cathode composites, as an interlayer on the separator, and as a protective coating on the anode. In Chapter 9, recent advances on the design and fabrication of CDG-based supercapacitor electrodes are addressed, with emphasis on the functionalization methods and their impact on the capacitive performance. To satisfy and match wearable electronics, Chapter 10 reviews the recent advances on CDG-based wearable energy conversion and storage devices, along with an outlook on the future development of this hot topic.

For clean and sustainable environmental development, Chapter 11 reviews the recent advances on CDG-based membranes for water purification and gas separation, accompanied by a discussion on the separation mechanisms and fabrication methods of such novel membranes. CDG is also an ideal platform for biosensing applications. In Chapter 12, the functionalization of CDG for biosensing is summarized. Different surface plasmon resonance (SPR) biosensing assays based on CDG-based immobilization matrices are reviewed, with a special emphasis on the deposition of linking layers and their advantages compared to the existing SPR interfaces. Chapter 13 focuses on the corrosion protection applications of CDG-based coating layers. The functionalization methods, properties, and underlying mechanisms of CDG as anti-corrosion coating materials are summarized, given its good impermeability and chemical inertness toward oxidizing gases or corrosive solutions.

This book is clearly multidisciplinary, spanning from the underlying functionalization principles to the cutting edge applications of graphene-based materials in different research fields. I hope this book will be a reference book and provide inspiration for graduate students, researchers, and engineers interested in CDG-based materials and their emerging applications.

I would like to thank the main chapter authors (L. Zhang, Y. Zhang, J.-B. Baek, D. Geng, X. Meng, Y. Zong, S.-P. Chai, L. Wang, J. Xu, X. Zhang, R. Dominko, J. Zhang, T. Chen, B. Bai, Y. Stebunov, H. Ma) and their co-workers who have really made the book attractive and rich in content, and also thanks to the Managers and Editors of the Royal Society of Chemistry for their generous help to publish this book. Finally, I dedicate this book to my family, especially to my wife Mrs Jizhen Ma, for their continuous encouragement and support.

Jintao Zhang

Shandong University, Jinan, China