MXene decorated by phosphorus-doped TiO2 for photo-enhanced electrocatalytic hydrogen evolution reaction

Ti3C2Tx (MXene) is adopted as a potential electrocatalyst for energy conversion owing to its outstanding conductivity and tunable chemical surface. However, its intrinsic poor chemical activities and limited active site densities are detrimental to corresponding reactions, for example hydrogen evolution reaction (HER). In this work, MXene decorated by phosphorus-doped TiO2 (P-TiO2@Ti3C2) was successfully designed and synthesized through in-situ phosphorus-doped TiO2 growth. Enhanced electronic conduction, extended light absorption, and promoted HER reaction kinetics were achieved by synchronously tuning phosphorous doping and oxygen vacancies (OVs). Compared with traditional MXene and corresponding derived materials, P-TiO2@Ti3C2 exhibited Vis-NIR photo-enhanced electrocatalytic HER activity with a small overpotential of 97 mV (at 10 mA cm(-2)) and a low Tafel slope of 48.4 mV dec(-1), which performed more efficient than that in darkness. Moreover, the as-synthesized catalyst offered a distinct advantage of long-term stability for more than 50 h along with light irradiation. This work provides a novel strategy for constructing MXenes materials with advantageous structures for extensive photo-electrochemical applications. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

In this study, MXene decorated with phosphorus-doped TiO2 (P-TiO2@Ti3C2) was successfully designed and synthesized, achieving enhanced electronic conduction, extended light absorption, and promoted HER reaction kinetics by synchronously tuning phosphorous doping and oxygen vacancies. P-TiO2@Ti3C2 exhibited excellent Vis-NIR photo-enhanced electrocatalytic HER activity with long-term stability under light irradiation.