Enhanced electrocatalytic hydrogen evolution of phase-modulated TiO2@MoS2 nanoporous flims decorated by Ni nanoclusters

Abstract

In this study, we present the fabrication and characterization of phase- and morphology-modulated TiO2 @MoS2 nanopore arrays with additional Ni decoration. The groundwork for these structures is established by the creation of highly ordered TiO2 nanoporous arrays through facile anodic oxidation, forming a background for the subsequent MoS2 nanosheet arrays. Enhanced conductivity within the heterostructure is achieved through a phase modulation of MoS2, transitioning from the 2 H phase to the 1 T phase via a hydrothermal exfoliation treatment. Notably, the introduction of Ni nanoclusters proves advantageous in preserving the 1 T phase during storage and cycling, thus enhancing stability during the performance of the hydrogen evolution reaction. Phase variation and different doping sites are proposed via theoretical calculation, where, smaller energy barriers are attained within the Ni-doped 1 T-MoS2 nanopores toward H+ to H2 transformation. Using the prepared TiO2 @MoS2-1 T + Ni electrode, an overpotential of 270 mV was achieved at a current density of 10 mA/cm², along with a Tafel slope of 63 mV dec⁻¹ .