Magnetic field-enhanced photoelectrochemical water splitting of Co3O4/TiO2 for efficient oxygen evolution

• Published in: Science China materials 2024-10, Vol.67 (10), p.3167-3175
• Main Authors: Zhou, Ze-En, Lu, Yi, Liu, Yi-Xuan, Cao, Shang, Tian, Ge, Hu, Zhi-Yi, Shen, Ling, Wu, Si-Ming, Ying, Jie, Geng, Wei, Yang, Xiao-Yu
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Chemistry/Food Science; Materials Science
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-024-3029-5

Effective separation of photogenerated carriers plays a vital role in governing the efficiency of photo-electrocatalytic reactions. However, the advancement in enhancing the intrinsic carrier separation efficiency of semiconductors has shown limited progress. Herein, we reported the use of a magnetic field to improve the photoelectrochemical water splitting of a magnetic Co 3 O 4 /TiO 2 photoanode by boosting the photogenerated carrier separation efficiency. In the presence of the magnetic field, oxygen evolution reaction occurs with a high photocurrent density of 0.86 mA cm −2 at 1.23 V versus V RHE , and an applied bias photon-to-current efficiency of 0.342% at 0.61 V RHE . Moreover, the photoanode maintains its oxygen evolution reaction for more than 400 h with photocurrent decays by ca. 10%. Observations made in this effort show that the enhancement of photo-electrocatalytic efficiency by a magnetic field is a consequence of the effect of the Lorentz force generated by the magnetic field on photogenerated carriers and ions near the Co 3 O 4 /TiO 2 photoanode, which improves the carrier separation efficiency and the bubble release rate. The results suggest that manipulating photoelectrode carriers by using a magnetic field is a promising strategy to design high-performance photoelectrochemical for water splitting.