A Review on Quantum Dots Modified g-C3N4-Based Photocatalysts with Improved Photocatalytic Activity

Yanling Chen,Xue Bai

doi:10.3390/catal10010142

Abstract

In the 21st century, the development of sustainable energy and advanced technologies to cope with energy shortages and environmental pollution has become vital. Semiconductor photocatalysis is a promising technology that can directly convert solar energy to chemical energy and is extensively used for its environmentally-friendly properties. In the field of photocatalysis, graphitic carbon nitride (g-C3N4) has obtained increasing interest due to its unique physicochemical properties. Therefore, numerous researchers have attempted to integrate quantum dots (QDs) with g-C3N4 to optimize the photocatalytic activity. In this review, recent progress in combining g-C3N4 with QDs for synthesizing new photocatalysts was introduced. The methods of QDs/g-C3N4-based photocatalysts synthesis are summarized. Recent studies assessing the application of photocatalytic performance and mechanism of modification of g-C3N4 with carbon quantum dots (CQDs), graphene quantum dots (GQDs), and g-C3N4 QDs are herein discussed. Lastly, challenges and future perspectives of QDs modified g-C3N4-based photocatalysts in photocatalytic applications are discussed. We hope that this review will provide a valuable overview and insight for the promotion of applications of QDs modified g-C3N4 based-photocatalysts.

Highlights

With rapid urban and societal development, environmental pollution and energy demands have become two major global challenges, attracting increasing research attention [1,2,3]
Results showed that coupling with Carbon quantum dots (CQDs) extended the optical absorption of UCN to carrier recombination enhanced possibility of charge carriers participatingand in photocatalytic the near-infrared (NIR)and region, whichthe efficiently inhibited carrier recombination enhanced the water splitting
2 evolution of 88.1 μmol h−1, possibility of charge carriers participating in photocatalytic water splitting

Summary

Introduction

With rapid urban and societal development, environmental pollution and energy demands have become two major global challenges, attracting increasing research attention [1,2,3]. As a metal-free semiconductor with a typical two-dimensional structure, graphitic carbon nitride (g-C3 N4 ) has received high levels of attention since Wang et al [29] first reported that g-C3 N4 exhibited excellent photocatalytic performance in water splitting under visible light irradiation in 2009 These findings contributed to the evidence that g-C3 N4 has relatively high thermal and chemical stability due to its tri-s-triazine ring structure and high degree of polymerization [30,31,32], and possesses an appropriate band gap (2.7 eV) and conduction band (CB) position (1.07 eV) [33,34]. Nm under an excitation wavelength of nm, photocatalytic technologies provide a promising method to solve these problems [4,5,6].and

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Results

Conclusion