Engineered Graphitic Carbon Nitride-Based Photocatalysts for Visible-Light-Driven Water Splitting: A Review

Abstract

Graphitic carbon nitride (g-C 3 N 4 ), a polymeric semiconductor, has become a rising star for photocatalytic energy conversion because of its facile accessibility, metal-free nature, low cost, and environmentally benign properties. This work reviews the latest progress of g-C 3 N 4 -based materials in visible-light-driven water splitting to hydrogen. It begins with a brief history of g-C 3 N 4 , followed by various engineering strategies of g-C 3 N 4 , such as elemental doping, copolymerization, crystalline tailoring, surface engineering, and single-atom modification, for elevated photocatalytic water decomposition. In addition, the synthesis of g-C 3 N 4 in different dimensions (0D, 1D, 2D, and 3D) and configurations of a series of g-C 3 N 4based heterojunctions (type II, Z-scheme, S-scheme, g-C 3 N 4 /metal, and g-C 3 N 4 /carbon heterojunctions) were also discussed for their improvement in photocatalytic hydrogen production. Lastly, the challenges and opportunities of g-C 3 N 4 -based nanomaterials are provided. It is anticipated that this review will promote the further development of the emerging g-C 3 N 4 -based materials for more efficiency in photocatalytic water splitting to hydrogen.

The biopolymer-assisted synthesis of assembled g-C3N4 open frameworks with electron delocalization channels for prompt H2 production

“…To overcome these disadvantages, several modification treatments have been developed and investigated, including constructing junctions, 9–12 doping with hetero- or homo-atoms 13–15 and controlling various microstructures. 16–18 Among these developed methods, controlling microstructures have attracted considerable research interest.…”

Effect of the cross-linker length of thiophene units on photocatalytic hydrogen production of triazine-based conjugated microporous polymers

“…Photocatalytic hydrogen evolution was rstly proposed by Honda and Fujishima in 1972 based on the potential applications of hydrogen, which has become a research hotspot in the academic eld. 3,4 In the last few decades, research mainly focused on metal-based inorganic semiconductor photocatalysts including TiO 2 , ZnO, CdS, GaP, and SiC. 5,6 However, metal-based inorganic semiconductor photocatalysts face many challenges, such as low photocatalytic activity, poor charge separation ability, high toxicity and the limitation of rare metals reserve.…”

Heptazine-Based π-Conjugated Materials for Light-Emitting

“…Over the last decade, considerable progress in the fields of organic light-emitting diodes (OLEDs) and photocatalysis has triggered intensive effort to develop highly efficient lightemitting materials and photocatalysts (Wu and Ma, 2016;Zhou et al, 2017;Zhou et al, 2019;Yin et al, 2020;Zhou et al, 2020). Among the many kinds of materials investigated, nitrogen-rich heptazine-based materials are highly attractive on account of intriguing photoelectronic and photocatalytic properties (Audebert et al, 2021;Wang et al, 2021). In the 1830s, heptazinebased materials were initially discovered by a Swedish chemist, Jons Jakob Berzelius, after the ignition of mercury thiocyanate, and this work was mentioned and reported by the German chemists, Justus von Liebg and Leopold Gmelin (Liebig, 1834;Gmelin, 1835;Liebig, 1835).…”