Co-Catalyst-Free Al6Si2O13/Cd8.05Zn1.95S10 Nanocomposites for Visible-Light-Driven Stable H2 Evolution and DDVP Degradation

The design of efficient and stable visible-light-driven photocatalysts is paramount for sustainable hydrogen (H2) evolution and the degradation of organophosphorus pesticides, exemplified by dichlorvos (DDVP). In this work, we synthesized a co-catalyst-free nanocomposite photocatalyst composed of Al6Si2O13 (ASO) and Cd8.05Zn1.95S10 (ZCS). By constructing a Type-I heterojunction, the optimized ASO/ZCS-1 nanocomposite (ASO loading ratio: 30%) enhanced visible-light-driven H2 evolution activity (5.1 mmol g−1 h−1), nearly doubling that of pristine ZCS (2.7 mmol g−1 h−1). Stability assessments revealed catalytic durability for ASO/ZCS-1 over five successive cycles, whereas the activity of pure ZCS precipitously declined to 59.7% of its initial level. Additionally, ASO, ZCS, and ASO/ZCS-2 (ASO loading ratio: 50%) demonstrated notable photocatalytic efficiency toward DDVP degradation without any co-catalyst, reducing DDVP concentration to 56.2% (ASO), 18.9% (ASO/ZCS-2), and 38.4% (ZCS), with corresponding degradation stability of 93.8%, 95.1%, and 93.8%, respectively. These results underscore the superior photocatalytic activity and stability of ASO, ZCS, and ASO/ZCS in the remediation of organophosphorus pesticides, with the Type-I heterojunction structure of ASO/ZCS enhancing both degradation activity and stability. Comprehensive characterizations by X-ray photoelectron spectroscopy (XPS), ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS), and differential charge density analyses verified the Type-I heterojunction charge-transfer mechanism, effectively suppressing charge recombination and thus improving photocatalytic performance. Consequently, ASO/ZCS nanocomposites exhibit significant promise for broad applications in sustainable H2 production, pollutant degradation, and ensuring food and agricultural product safety.