Enhancement of photocatalytic activity by semiconductor heterojunctions: α-Fe2O3, WO3 and CdS deposited on ZnO

High-temperature steam reforming of methanol over ZnO–Al2O3 catalysts

“…There is intense absorption below the wavelength of 400 nm for commercial and self-prepared ZnO, which is known as a strong absorption of ZnO. This absorption is corresponded to a charge-transfer process from the valence band (O 2p orbits) to the conduction band (Zn 4s orbits) [45,46]. The absorption spectra of ZnO-96, ZnO-88, ZnO-75 and ZnO-67 show the characteristic absorption of ZnO.…”

Quantum Size Effects in Semiconductor Photocatalysis

“…At the present time a fairly wide group of double composites having enhanced photocatalytic or photoelectrochemical activity compared with the individual components have been described: CdS/TiO 2 [60,[61][62][63][64][65][66][67][68][69][70], CdSe/TiO 2 [71], CdS/M x S y (M x S y = Bi 2 S 3 , Sb 2 S 3 , Cu x S, Ag 2 S) [72][73][74][75], CdS/ZnO [75][76][77][78][79][80], CdS/AgI [77], CdS/ZnS [45,81], ZnO/SnO 2 [82,83], WO x /TiO 2 , WO x /ZnO [84][85][86], CeO 2 /TiO 2 [87,88], Cu 2 O/ZnO [89], InP/TiO 2 [90], Cd 3 P 2 /TiO 2 , Cd 3 P 2 /ZnO [91], MoS 2 /TiO 2 , WS 2 /TiO 2 [92], etc. Examples of photocatalytic reactions with the participation of such nanocomposites have been discussed in reviews [4,5,73,93].…”

Characterization and photoactivity of coupled ZnO–ZnWO4 catalysts prepared by a sol–gel method

“…ZnO has been coupled to various semiconductors such as ZnO-TiO 2 [11][12][13], ZnO-CdS [14,15], ZnO-SnO 2 [16][17][18][19][20][21] to improve its photocatalytic activity. Only few publications have concerned the synthesis of ZnO-ZnWO 4 [22,23] and ZnO-ZnWO 4 -WO 3 [24] photocatalysts to be employed for the photodegradation of organic compounds.…”