Ti3C2Tx MXene-derived amorphous TiO2-C nanosheet cocatalysts coupled CdS nanostructures for enhanced photocatalytic hydrogen evolution

Developing non-noble-metal cocatalysts is essential for the large-scale implementation of solar-driven H 2 production technology, but still remains a great challenge. In this work, Ti 3 C 2 T x MXene coupled CdS nanostructures are fabricated via one-step gamma-ray radiation-induced reduction in ambient conditions. By subsequent alkaline treatment, a novel cocatalyst of carbon supported amorphous TiO 2 nanosheets (denoted as aTiO 2 -C) is derived from Ti 3 C 2 T x /CdS to form aTiO 2 -C/CdS nanocomposites. The prepared aTiO 2 -C/CdS nanocomposites with cyclability achieve a H 2 evolution rate of 1.48 mmol·g −1 ·h −1 under visible-light illumination, which is 6.4 and 7.0 times greater than that of pristine Ti 3 C 2 T x /CdS and P-CdS, respectively. The oxygen vacancies in aTiO 2 -C cocatalysts are revealed to act as electron trapping sites to facilitate the transfer of photoexcited electrons and boost photoactivity. Further, the electronic interaction between CdS and aTiO 2 -C prevents Cd 2+ from leaching and thus enhances photostability. The results of this work may guide the rational design of viable cost-effective cocatalysts in solar-to-chemical energy conversion and beyond.