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

A series of visible light responsive nanorods of InGaZn mixed oxide photocatalyst are designed by varying the concentration of In(NO3)(3) via 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 Vat 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.