Enhanced photoelectrochemical water splitting performance by CoFe2S4/TiO2 nanotubes p-n type heterojunction

Abstract

Earth-abundant photoelectrocatalyst with better photocatalytic activity and maximum stability are in greater demand for realizing systematic sustainable and efficient photocatalytic water splitting. Chalcogenides with suitable atomic arrangement and having high electronic transport, show unique interesting catalytic properties in overall photoelectrochemical water splitting. Here, a fabrication of multi-elements composition were proposed to develop CoFe2S4/TiO2 nanotubes (NTs) heterojunction using anodization, followed by SILAR method and then its sulfurization via CVD technique. The synthesized photocatalyst were characterized using an X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), UV-Vis-Diffuse reflectance spectroscopy (UV-Vis-DRS), Fourier transform infrared spectroscopy (FTIR) and Photoluminescence (PL) spectroscopy. Photoelectrochemical results determines that 15- CoFe2S4/TiO2 NTs have excellent photocurrent density of 2.95 mAcm-2, as compared to pure TiO2 NTs (0.78 mAcm-2), 05-CoFe2S4/TiO2 NTs (1.04 mAcm-2), 10-CoFe2S4/TiO2 NTs (1.75 mAcm-2), and 20-CoFe2S4/TiO2 NTs (2.30 mAcm-2) respectively at 0.3V vs Ag/AgCl (1.23V vs RHE) using 100 mWcm-2 light intensity without UV-Vis light filter. The better photocatalytic performance of 15-CoFe2S4/TiO2 NTs is because of the optimized loading of CoFe2S4 over TiO2 NTs having proper atomic arrangement and morphology, which is thus helpful in efficient charge separation and transportation with unique redox capability.