Chlorophyll derivative sensitized monolayer Ti3C2Tx MXene nanosheets for photocatalytic hydrogen evolution

Abstract

Hydrogen production by photocatalytically splitting water is considered as a promising strategy for solar to chemical energy conversion to solve global energy problems. Ti3C2Tx is a two-dimensional transition metal titanium carbide material with excellent electrochemical properties. Nevertheless, the application of Ti3C2Tx as a co-catalyst in photocatalysis presents many challenges, which is mainly due to its lower photocatalytic activity. In this work, monolayer Ti3C2Tx nanosheets were prepared as efficient co-catalysts for the photocatalytic water splitting for H2 evolution through the delamination and exfoliation process of pristine two-dimensional titanium carbide Ti3C2Tx MXene. In addition, a chlorophyll-a derivative (Chl) was used as an effective visible light harvester by a simple one-step deposition process on monolayer Ti3C2Tx nanosheets, and a novel noble metal-free Chl@monolayer Ti3C2Tx photocatalyst was successfully synthesized for the photocatalytic water splitting to hydrogen evolution reaction (HER). It was found that the optimal Chl@monolayer Ti3C2Tx composite had the best HER performance as high as 106 μmol/h/gcat, which was much higher than that of the pristine Chl@Ti3C2Tx composite.