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

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 Ti₃C₂T _x (the MXene phase) via a simple solvothermal process during which Ti₃C₂T _x was partially oxidized to form anatase TiO₂ nanoparticles. The obtained Ti₃C₂T _x /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 Ti₃C₂T _x 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.

SUBMITTER: Hao N 

PROVIDER: S-EPMC9080836 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature