Modulation of the photocatalytic activity of MAPbI3 crystals via Nb2CTx MXenes for high-efficiency photocatalytic hydrogen production

Abstract

This study addresses rapid charge recombination and instability in MAPbI₃ photocatalysts for hydrogen production by constructing a Nb₂CT_x MXenes-modulated composite. Leveraging Nb₂CT_x metallic conductivity for efficient electron extraction and proton reduction sites, the composite enables robust photocatalytic HI splitting in strong acid. In situ coupling achieved intimate heterointerface contact with Z-scheme characteristics, yielding a remarkable hydrogen evolution rate of 12 046.77 μmol h⁻¹ g⁻¹—a 344-fold enhancement over pristine MAPbI₃—while retaining ∼85% activity after 5 cycles. UPS and theoretical calculations confirm a strong built-in electric field at the heterointerface accelerates carrier separation. Critically, the Z-scheme simultaneously suppresses recombination and preserves strong redox capabilities. This interface engineering synergistically enhances efficiency and stability, resolving the charge separation-redox capability trade-off in conventional type II heterojunctions.