Ti₃C₂Tₓ-engineered MoS₂/SiNWs multifunctional photocathode for Photoelectrochemical hydrogen generation and wastewater remediation

Abstract

The development of efficient and durable photocathodes for integrated hydrogen generation and wastewater treatment remains a critical challenge in photoelectrochemical (PEC) systems. This study pioneers a Ti₃C₂Tₓ MXene-engineered MoS₂/SiNWs photocathode, leveraging the superior charge transport, catalytic activity, and stability of MXenes to address the persistent limitations of MoS₂-based systems. The optimized Ti₃C₂Tₓ/MoS₂/SiNWs heterostructure demonstrates a remarkable photocurrent density of −0.10 mA/cm² at 0 V vs. RHE and an incident photon-to-current efficiency (IPCE) of 38.12 %, nearly doubling the performance of conventional MoS₂/SiNWs photocathodes. Additionally, it achieves an 80.80 % degradation of methylene blue (MB), reducing total organic carbon (TOC) to 1.52 mg/mL, while sustaining a hydrogen evolution rate of 9.32 μmol/h at −0.75 V vs. RHE. Electrochemical impedance spectroscopy (EIS) reveals an ultra-low charge transfer resistance of 102 Ω, confirming the enhanced charge separation and suppressed recombination losses. Mechanistic studies establish an S-scheme charge transfer pathway, where Ti₃C₂Tₓ synergistically promotes electron transport while facilitating reactive oxygen species (ROS)-driven organic degradation. This work advances the frontier of multifunctional PEC photocathodes by providing a scalable, high-efficiency platform for simultaneous sustainable hydrogen production and environmental remediation.