Enhanced photocatalytic H2 generation and Cr(vi) reduction by a sheet-on-sheet Cd(OH)2/CdS nanocomposite

Abstract

The advancement of efficient photocatalysts is essential for tackling global energy and environmental issues. In this work, a unique sheet-on-sheet Cd(OH)₂/CdS photocatalyst was synthesized via a facile solution strategy, demonstrating significantly improved photocatalytic performance for H₂ generation and Cr(VI) reduction. The optimal 5% Cd(OH)₂/CdS obtained an impressive H₂ production rate of 3475 μmol g⁻¹ h⁻¹ under visible light, marking a 6.3 times increase compared to CdS. Additionally, the kinetics of Cr(VI) reduction were markedly accelerated, with a rate constant of 0.2803 min⁻¹, representing a 5.7 times improvement over pure CdS. Moreover, the 2D/2D Cd(OH)₂/CdS photocatalyst exhibited exceptional stability, maintaining high photocatalytic activity over multiple reaction cycles. Experimental findings and DFT calculations revealed the charge transfer mechanism between CdS nanosheets and Cd(OH)₂ cocatalyst. This work provides insights into designing high-performance CdS-based nanophotocatalysts for water splitting and environmental remediation.