g‐C₃N₄‐Based Heterostructured Photocatalysts

Abstract

Thereafter, the photocatalytic degrada tion of polychlorobiphenyls [2] and photo electrocatalytic reduction of CO 2 into hydrocarbon compounds [3] in aqueous semiconductor suspensions greatly broad ened the applications of photocatalysis. Although the photocatalytic technology has got worldwide attention for its eco nomic, clean, safe, and renewable charac teristics, the photocatalytic performance of currently known photocatalysts is still far from commercial applications, especially in solartofuel conversion. [4][5][6][7][8][9][10][11] Generally, the photocatalytic reactions can be divided into three basic processes. First, the semiconductor photocatalysts absorb effective photons whose energy (h v ) is equal to or above their bandgap (E g ), resulting in the generation of electronhole pairs. Second, the photogenerated charge carriers separate and transfer to the surface of photocatalysts. Third, the photogenerated electrons and holes partic ipate in reactions of substances adsorbed on the surface of the photocatalysts. [12,13] Thus, the improvements of the three aforementioned processes play impor tant roles in enhancing the photocatalytic performance. Light absorption is the first essential step of photocatalysis process. The traditional anatase phase TiO 2 photocatalyst is active only under UV light with wavelength below 387 nm due to its wide bandgap (3.2 eV). However, solar energy is mainly concentrated in the visible light region, and UV light accounts for less than 4% of the solar spectrum. [7] In order to achieve maximum utilization efficiency of solar energy, the exploration of visiblelightresponsive photo catalysts is an urgent task. Graphitic carbon nitride (gC 3 N 4 ) as a promising visiblelightresponsive photocatalyst has received worldwide attention due to its fascinating merits, such as moderate bandgap (≈2.7 eV), proper electronic band structure, nontoxicity, low cost, good stability, and easy preparation. [14][15][16][17][18] Since the first report on photocatalytic H 2 evolution over gC 3 N 4 by Wang et al. in 2009, [19] research endeavors toward improving the photocatalytic performance of gC 3 N 4 based photocatalysts have formed a forefront of photocatalysis research. [20][21][22][23][24][25] Bulk gC 3 N 4 powder can be prepared by the thermal poly condensation of lowcost nitrogencontaining organic pre cursors, e.g., urea, thiourea, melamine, cyanamide, dicyan diamide, guanidine hydrochloride, and so on. [26][27][28][29][30][31][32] The pure bulk gC 3 N 4 prepared by this method suffers from several shortcomings, including low specific surface area, insufficient visible light utilization, and, particularly, rapid recombination Photocatalysis is considered as one of the promising routes to solve the energy and environmental crises by utilizing solar energy. Graphitic carbon nitride (g-C 3 N 4 ) has attracted worldwide attention due to its visible-light activity, facile synthesis from low-cost materials, chemical stability, and unique layered structure. However, the pure g-C 3 N 4 photocatalys...

g-C3N4-Based Nanomaterials for Visible Light-Driven Photocatalysis

“…The Au surface plasmon resonance broadens the optical adsorption range, while Pt acts as a sink for photoexcited electrons. The combination of noble metals and g-C 3 N 4 enables tunable heterojunctions with improved charge transport than traditional nanocomposites [237][238][239][240][241][242][243], and such multicomponent heterostructures are a promising solution to environmental depollution [39,40,42], for example g-C 3 N 4 /Ag 3 PO 4 systems for MO degradation [242,243]. Ag 3 PO 4 @g-C 3 N 4 core-shell photocatalysts have also been applied to MB degradation under visible light, achieving 97% conversion in 30 min compared with only 79% for a physical mixture of the Ag 3 PO 4 and g-C 3 N 4 components, and 69% for pure Ag 3 PO 4 .…”

Graphitic Carbon Nitride with Dopant Induced Charge Localization for Enhanced Photoreduction of CO2 to CH4

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has become a star in water splitting [3][4][5][6][7] and CO 2 reduction. [8][9][10] Although many studies have been widely carried out, its CO 2 reduction performance is still far from the actual application requirements and the product is mainly CO (2-electron reduction product), [11,12] due to the high recombination rate of charge carriers and low reaction dynamics.

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1D/2D TiO2/MoS2 Hybrid Nanostructures for Enhanced Photocatalytic CO2 Reduction

“…[1][2][3][4][5][6][7] This approach can recycle CO 2 back to rene wable fuels by using solar energy which is green and inexhaustible. Photocatalytic CO 2 reduction over photocatalysts is a promising approach to overcome these two crises.…”