Facile synthesis of InGaZn mixed oxidenanorods for enhanced hydrogen production under visible light

Abstract

A series of visible light responsive nanorods of InGaZn mixed oxide photocatalyst are designed by varying the concentration of In(NO₃)₃via a solid state reaction method without the need for a surfactant or template. The photocatalysts are characterized by XRD, diffuse reflectance UV-vis spectra, TEM, BET surface area analysis, PL, and photoelectrochemical measurement. Increasing the concentration of In(NO₃)₃ changes the morphology from agglomerated to nanorod-shaped, and reduces surface defects which inhibits the recombination of charge carriers. From photocurrent measurements, the conduction band minimum and valance band maximum of InGaZn (3 : 1 : 1) are found to be −0.75 and 1.65 V at pH 5.9, respectively, which is suitable for oxidation and reduction processes. The photocatalysts are tested towards hydrogen generation under visible light irradiation. Among all the photocatalysts, InGaZn (3 : 1 : 1) gives the best result towards the production of hydrogen energy under visible light irradiation.