Ultrafine nano 1T-MoS2 monolayers with NiOx as dual co-catalysts over TiO2 photoharvester for efficient photocatalytic hydrogen evolution

Abstract

Molybdenum disulfide (MoS2) of 1 T phase was found to potentially replace Pt as efficient co-catalyst for the hydrogen evolution reaction (HER). Herein, an ultrafine nano 1 T-MoS2 monolayer of around 10 nm was successfully synthesized and showed a high electrocatalytic HER activity with low overpotential of 78 mV at 10 mA cm−2. When the 1 T-MoS2 is loaded onto P25 TiO2, its ultrafine size dramatically promotes the superior interface bonding with TiO2 and a high photocatalytic HER activity of 300.3 μmol h−1 is obtained. Furthermore, a strategy by introducing NiOx co-catalyst into the 1 T-MoS2/P25 to fabricate a dual co-catalyst composite 1 T-MoS2/P25/NiOx significantly improves the photocatalytic HER activity to 1629.1 μmol h-1 which is very close to Pt/P25 of 2196.8 μmol h-1. The close interface-bonding between the nanosized 1 T-MoS2 monolayer and P25 along with the assistance of NiOx results in the superior photocatalytic HER activity by the enhanced separation and transfer of the photogenerated electrons and holes.