Comparative Study of RF Sputtered Ba2(BiNb)O6 and Ba2Bi1.4Nb0.6 O6 thin films and Effect of Fluorine Doping in Their Photoelectrochemical (PEC) Performances

TL;DR

This study compares RF sputtered Ba2(BiNb)O6 and Ba2Bi1.4Nb0.6O6 thin films, examining how fluorine doping enhances their photoelectrochemical water splitting efficiency through surface treatments and material modifications.

Contribution

It introduces a method to synthesize barium bismuth niobate thin films and demonstrates how fluorine doping improves PEC performance and stability.

Findings

Higher photocatalytic activity after surface treatments

Fluorine doping increases photocurrent density

Enhanced electrode stability against corrosion

Abstract

Bismuth based ternary oxide photocatalysts are of considerable interest in photoelectrochemical water splitting. Yet these oxides are highly stable in different environment, their relative inertness limits the available synthesis routes to obtain desired stoichiometry on the final product. This report describes a method to prepare barium bismuth niobate (specifically, Ba2(BiNb)O6 and Ba2Bi1.4Nb0.6 O6) target by sintering a mixture of individual oxides and successfully fabricate desired barium bismuth niobate thin film on TCO substrate. The surface morphology, physical, and chemical properties of thin film were systematically investigated. Compositional uniformity was obtained by sputtering in oxygen argon plasma environment and higher photocatalytic activities were observed after subsequent surface treatments. Sodium fluoride surface treatment further enhanced the photocurrent density and improved electrode stability against corrosion. This work further suggests a viable approach to improve the PEC performance of sputtered barium bismuth niobate by modulating their fundamental energy states.