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

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.