In-situ synthesized oxygen vacancy filled ZnS/Vo-ZnO heterojunction photocatalysts for efficient H2 production

A comprehensive review of oxygen vacancy modified photocatalysts: synthesis, characterization, and applications

“…In the field of semiconductor photocatalytic technology, the process of photocatalysis involves three distinct steps: (1) generation of photoexcited charges -where photons are absorbed by the semiconductor material leading to the creation of electronhole pairs; (2) separation and transportation of chargeswherein photoexcited electron-hole pairs undergo segregation within the bulk phase of the catalyst and migrate towards the surface of the photocatalysts; and (3) occurrence of surface reactions -involving redox reactions between electrons and holes taking place on the surface of the photocatalysts. Metal oxide semiconductors, such as TiO 2 , 2-13 ZnO, [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] WO 3 , [29][30][31][32] BiOX, [33][34][35] In 2 O 3 , [36][37][38][39][40][41] SnO 2 , [42][43][44][45][46][47] and CuO [48][49][50][51][52][53] have been extensively investigated as photocatalysts due to their exceptional stability under light irradiation. However, their photocatalytic performance remains limited by inadequate absorption of visible light, the propensity of carriers to recombine during migration, and high-energy barriers for reactant capture and activation.…”