A Cobalt@Cucurbit[5]uril Complex as a Highly Efficient Supramolecular Catalyst for Electrochemical and Photoelectrochemical Water Splitting

• Published in: Angewandte Chemie International Edition 2021-01, Vol.60 (4), p.1976-1985
• Main Authors: Li, Fusheng, Yang, Hao, Zhuo, Qiming, Zhou, Dinghua, Wu, Xiujuan, Zhang, PeiLi, Yao, Zhaoyang, Sun, Licheng
• Format: Article
• Language: English
• Subjects: Bismuth compounds; Catalysts; Charge recombinations; Charge transfer; electrocatalysis; Electrochemistry; Electrolytes; host–guest complexes; Indium compounds; Interfacial charge transfer; Light illumination; PEC cells; Photocurrents; Photoelectrochemical water oxidation; Photoelectrochemical water splitting; Semiconducting bismuth compounds; supramolecular catalysts; Supramolecular chemistry; Tin oxides; Turnover frequency; Water oxidation catalysts; water splitting
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202011069

A host–guest complex self‐assembled through Co2+ and cucurbit[5]uril (Co@CB[5]) is used as a supramolecular catalyst on the surface of metal oxides including porous indium tin oxide (ITO) and porous BiVO4 for efficient electrochemical and photoelectrochemical water oxidation. When immobilized on ITO, Co@CB[5] exhibited a turnover frequency (TOF) of 9.9 s−1 at overpotential η=550 mV in a pH 9.2 borate buffer. Meanwhile, when Co@CB[5] complex was immobilized onto the surface of BiVO4 semiconductor, the assembled Co@CB[5]/BiVO4 photoanode exhibited a low onset potential of 0.15 V (vs. RHE) and a high photocurrent of 4.8 mA cm−2 at 1.23 V (vs. RHE) under 100 mW cm−2 (AM 1.5) light illumination. Kinetic studies confirmed that Co@CB[5] acts as a supramolecular water oxidation catalyst, and can effectively accelerate interfacial charge transfer between BiVO4 and electrolyte. Surface charge recombination of BiVO4 can be also significantly suppressed by Co@CB[5]. A host–guest complex self‐assembled through Co2+ and cucurbit[5]uril (Co@CB[5]) is used as a supramolecular catalyst on the surface of metal oxides including porous indium tin oxide (ITO) and porous BiVO4 for efficient electrochemical and photoelectrochemical water oxidation.