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

• 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].

Ämnesord

NATURVETENSKAP  -- Kemi -- Materialkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Materials Chemistry (hsv//eng)

Nyckelord

electrocatalysis

host–guest complexes

PEC cells

supramolecular catalysts

water splitting

Bismuth compounds

Catalysts

Charge transfer

Electrochemistry

Electrolytes

Indium compounds

Photocurrents

Supramolecular chemistry

Tin oxides

Charge recombinations

Interfacial charge transfer

Light illumination

Photoelectrochemical water oxidation

Photoelectrochemical water splitting

Turnover frequency

Water oxidation catalysts

Semiconducting bismuth compounds

Publikations- och innehållstyp

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