In situ hybridization of an MXene/TiO2/NiFeCo-layered double hydroxide composite for electrochemical and photoelectrochemical oxygen evolution?

RSC Advances Pub Date: 2018-06-05 DOI: 10.1039/C8RA02349B

Abstract

Electrochemical and photoelectrochemical (PEC) oxygen evolution reactions (OER) are receiving considerable attention owing to their important roles in the overall water splitting reaction. In this contribution, ternary NiFeCo-layered double hydroxide (LDH) nanoplates were in situ hybridized with Ti3C2Tx (the MXene phase) via a simple solvothermal process during which Ti3C2Tx was partially oxidized to form anatase TiO2 nanoparticles. The obtained Ti3C2Tx/TiO2/NiFeCo-LDH composite (denoted as TTL) showed a superb OER performance as compared with pristine NiFeCo-LDH and comercial IrO2 catalyst, achieving a current density of 10 mA cm?2 at a potential of 1.55 V versus a reversible hydrogen electrode (vs. RHE) in 0.1 M KOH. Importantly, the composite was further deposited on a standard BiVO4 film to construct a TTL/BiVO4 photoanode which showed a significantly enhanced photocurrent density of 2.25 mA cm?2 at 1.23 V vs. RHE under 100 mW cm?2 illumination. The excellent PEC-OER performance can be attributed to the presence of TiO2 nanoparticles which broadened the light adsorption to improve the generation of electron/hole pairs, while the ternary LDH nanoplates were efficient hole scavengers and the metallic Ti3C2Tx nanosheets were effective shuttles for transporting electrons/ions. Our in situ synthetic method provides a facile way to prepare multi-component catalysts for effective water oxidation and solar energy conversion.

Graphical abstract: In situ hybridization of an MXene/TiO2/NiFeCo-layered double hydroxide composite for electrochemical and photoelectrochemical oxygen evolution
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