Ordered Ti-doped FeVO4 nanoblock photoanode with improved charge properties for efficient solar water splitting

Highly photoactive FeVO4 photoanodes with ordered nanoblock morphology and uniform Ti-doping were prepared by drop-casting mixed Ti and V precursors onto FeOOH nanorod films and following an annealing process. The results indicate that Ti4+ is uniformly doped into the FeVO4 lattice by substituting V5+ and provides an increased number of O-2(-) vacancies. The optimized film thickness and doping level are 620 nm and 0.3%, respectively. Compared to the undoped sample, the Ti-doped photoanode showed -219% enhancement in photocurrent at 1.0 V vs Ag/AgCl under back illumination of AM 1.5, reaching a state-of-the-art value of -1.47 mA cm(-2), and also achieved stable and efficient overall water splitting activity with evolution rates of 28.3 and 14.1 mu mol cm(-2)h(-1) for H-2 and O-2, respectively. The excellent PEC performance could be attributed to the remarkably enhanced charge carrier concentration and conductivity, and the facilitated charge transfer kinetics across the semiconductor/electrolyte interface, as a result of Ti-doping. (c) 2021 Elsevier Inc. All rights reserved.

Automated summary

Highly photoactive FeVO4 photoanodes with ordered nanoblock morphology and uniform Ti-doping were prepared, showing enhanced photocurrent and overall water splitting activity. The Ti4+ successfully doped into the FeVO4 lattice by substituting V5+ increased the number of O-2(-) vacancies, leading to improved charge carrier concentration and conductivity, and facilitated charge transfer kinetics.