Eco-friendly and facilely prepared silica modified amorphous titania (TiO2–SiO2) electrocatalyst for the O2 and H2 evolution reactions

Abstract

An eco-friendly silica modified amorphous titania (TiO₂–SiO₂) electrocatalyst is prepared. This silica modified amorphous titania (TiO₂–SiO₂) composite material is prepared by facile spurting of silica (obtained from a sustainable resource) over a titanium plate and identified as an active electrocatalyst for O₂ and H₂ evolution by water oxidation. The prepared composite shows a maximum current density of 12 mA cm⁻² at 2 V (versus RHE) in 1 M KOH electrolyte. This is because the semiconductor heterostructure of the structurally and chemically dissimilar amorphous TiO₂–SiO₂ composite introduces new collective electronic states with improved electrical conductivity, with a decrease in the work function. The catalytic activity is found to be stable in continuous operation for about 10 h. The physicochemical characterization of the electrocatalyst was carried out using scanning electron microscopy, energy dispersive X-rays, X-ray diffraction, X-ray photoelectron spectra, and electron paramagnetic resonance and the work function was examined by a Scanning Kelvin Probe. Because of the simple, cheap, and scalable preparation procedure, the electrocatalyst is highly promising for practical low cost and high technology applications. Interestingly, the system is active in the oxygen and hydrogen evolution reactions, leading to a promising bifunctional electrocatalyst.