MoS₂ Quantum Dots Modified Black Ti³⁺–TiO₂/g‐C₃N₄ Hollow Nanosphere Heterojunction toward Photocatalytic Hydrogen Production Enhancement

Abstract

The MoS 2 quantum dots (QDs) modified black Ti 3þ -TiO 2 /g-C 3 N 4 hollow nanosphere heterojunction is synthesized via the continuous chemical template deposition and sculpture-reduction processes. The results of structural characterizations imply that the Ti 3þ -TiO 2 /g-C 3 N 4 /MoS 2 QDs hollow nanosphere heterojunction is prepared successfully. The photocatalytic hydrogen evolution reaction (HER) of the B-TiO 2 /g-C 3 N 4 /MoS 2 QDs (%1524.37 μmol g À1 h À1 ) exhibits an enhancement of %33 folds compared with the normal TiO 2 . Furthermore, the process of photocatalysis and the mechanism of photocatalytic HER enhancement are explored, which can be ascribed to the HER activity sites of MoS 2 QDs, Ti 3þ /O v ions in the Ti 3þ -TiO 2 , and hollow nanosphere heterojunction, which are proved by electrochemical measurements.

Defect Engineering of Photocatalysts for Solar Energy Conversion

“…Generally, solar energy conversion system always involves three different steps about charge generation, charge separation, and catalytic reactions . A substantial proportion of the efforts were conducted to exploit the promising semiconductors . However, the low efficiency is mainly ascribed to wide bandgap, poor charge transfer, and poor stability.…”

Construction of an Ultrathin S‐Scheme Heterojunction Based on Few‐Layer g‐C3N4 and Monolayer Ti3C2Tx MXene for Photocatalytic CO2 Reduction

“…Among the semiconductors with high valence band (VB) potential, TiO 2 , as an ultraviolet‐responsive semiconductor with a bandgap of 3.2 eV, is the most studied photocatalytic semiconductor. [ 24–28 ] As its energy band structure is capable of forming S‐scheme with g‐C 3 N 4 , a wide range of g‐C 3 N 4 /TiO 2 composites have been synthesized for CO 2 reduction, [ 27 ] organics degradation, [ 29–33 ] H 2 production, [ 34,35 ] and N 2 O decomposition. [ 36 ] Although the g‐C 3 N 4 /TiO 2 composites have various morphologies, the contact modes of g‐C 3 N 4 and TiO 2 can be simply classified as point‐to‐face contact [ 32 ] and face‐to‐face contact.…”

“…[ 36 ] Although the g‐C 3 N 4 /TiO 2 composites have various morphologies, the contact modes of g‐C 3 N 4 and TiO 2 can be simply classified as point‐to‐face contact [ 32 ] and face‐to‐face contact. [ 27,29,37 ] As the specific 1D electron transfer and narrow point‐to‐face transfer channel greatly reduce the electron transfer efficiency, an efficient face‐to‐face contact was adopted in more g‐C 3 N 4 /TiO 2 composites. As the intensity of light decays exponentially in a semiconductor, g‐C 3 N 4 /TiO 2 composites with hollowsphere structure, [ 37 ] porous structure, [ 38 ] and flower structure [ 39 ] were widely prepared to increase their specific surface area.…”

“…[ 27,29,37 ] As the specific 1D electron transfer and narrow point‐to‐face transfer channel greatly reduce the electron transfer efficiency, an efficient face‐to‐face contact was adopted in more g‐C 3 N 4 /TiO 2 composites. As the intensity of light decays exponentially in a semiconductor, g‐C 3 N 4 /TiO 2 composites with hollowsphere structure, [ 37 ] porous structure, [ 38 ] and flower structure [ 39 ] were widely prepared to increase their specific surface area. However, the instinctive agglomeration of flexible layered g‐C 3 N 4 still hinders its combination with TiO 2 .…”

NiSe2/CdS composite nanoflakes photocatalyst with enhanced activity under visible light

“…1 So, converting solar energy into hydrogen energy and degrading pollutants under light are constructive solutions. [2][3][4][5][6][7] The realization of the above technologies requires the use of photocatalysts. The earliest developed photocatalytic material was TiO 2 .…”