Energy and environmental applications of Sn4+/Ti4+ doped α-Fe2O3@Cu2O/CuO photoanode under optimized photoelectrochemical conditions.

Abstract

The most promising technique for directly converting solar energy into clean fuels and environmental remediation by organic dye degradation is photoelectrochemical (PEC) process. We introduced Sn4+/Ti4+ doped α-Fe2O3@CuxO heterojunction photoanode with complete optimization for PEC hydrogen (H2) generation and organic dye degradation. Improvement of photocurrent photo and reducing overpotentials under optimized conditions lead to enhancing PEC performances, degradation efficiency of organic compounds, and H2 generation generation rate. The optimized heterojunction photoanode (5TiFe@CuxO-D) showed IPCE exceeding 42% compared with pristine hematite (Fe0.01-8006h) nanostructures (28%). Additionally, all the optimized photoanodes showed higher PEC stability for 10h. Time-resolved PL spectra confirm the improved average lifetime for heterojunction photoanodes, supporting the enhanced PEC performance. Optimized 5TiFe@CuxO-D material achieved PEC H2 generation of ∼300μLh-1.cm-2 which is two times higher than pristine hematite's activity (150μLh-1.cm-2) and almost 99% degradation efficiency within 120min of irradiation time. Therefore, a state-of-the-art study has been explored for hematite-based heterojunction photoanodes reflecting the superior PEC performance and hydrogen, methyl orange (MO) dye degradation activities. The improved results were reported because of stable morphology and better crystallinity acquired through systematic investigation of thermal effects and hydrothermal duration, improved electrical properties by Sn/Ti doping into the lattice of α-Fe2O3 and optimization of CuxO deposition methods. The formation of well-defined heterojunction minimizes the recombination of the charge carrier and leads to effective transportation of excited electrons for the enhanced PEC performance.