Fabrication of NiO/Ta₂O₅composite photocatalyst for hydrogen production under visible light

Abstract

SUMMARY A series of novel composite photocatalysts, NiO/Ta2O5, were synthesized by the solid‐state reaction and successfully characterized by X‐ray diffraction, Transmission electron microscopy, diffused reflectance ultraviolet and visible (DRUV‐vis) spectroscopy, Photoluminescence and X‐ray photoelectron spectroscopy. Powder X‐ray diffraction (PXRD) pattern indicated the formation of composite material. The red shift in the absorption edges of the newly prepared composite photocatalysts were well observed from the DRUV‐vis spectra. The composite photocatalyst prepared at metal ratio (1:3) showed highest result toward hydrogen production under ultraviolet and visible light irradiation in the presence of methanol as a sacrificial agent. Copyright © 2011 John Wiley & Sons, Ltd.

Fabrication of nano N-doped In2Ga2ZnO7 for photocatalytic hydrogen production under visible light

“…Among all the prepared photocatalysts, N-GaInZn-500 has high surface area of 71 m 2 /g. Thus more adsorption sites and photocatalytic centres are available for photocatalytic reaction [23,24,30]. The surface interaction of the photocatalyst and the reactant molecules are more in the case of N-GaInZn-500 which causes high photocatalytic activity towards hydrogen production under visible light.…”

“…At liquid N 2 temperature, the PL spectra of neat and N-GaInZn-500 photocatalysts are recorded with excitation at 300 nm. The PL emission spectra are generally used to know the efficiency of charge carrier trapping, migration and separation as it is generated from the recombination of photoinduced charge carriers [16,30]. Thus, the lower PL intensity shows lower recombination rate of photoinduced charge carriers [30,37,38].…”

“…Among all photocatalysts, NGaInZn-500 exhibits high surface area of 71 m 2 /g and NGaInZn-700 has lowest surface area of 42 m 2 /g. The former photocatalyst has more active sites on the surface for adsorption of reactant molecules and consequently results in higher photocatalytic activity [24,30,31].…”

“…Thus, photoinduced charge carriers can have much i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 3 7 ( 2 0 1 2 ) 1 7 9 3 6 e1 7 9 4 6 chance to reach to surfaces in advance of recombination and get captured to initiate photochemical reactions [23,29e31]. NGaInZn-500 can effectively inhibit the recombination of charge carriers [23,29,30].…”

“…The low PL intensity of NGaInZn-500 indicates that the recombination of photoinduced charge carriers is minimum as compared to other photocatalysts. The lowest recombination of photoinduced charge carriers results in higher photocatalytic activity towards hydrogen generation reaction under visible light irradiation [16,30,37]. …”