Enhanced Charge Transfer Dynamics in a NiCo₂S₄-Zn_xCd_1-xS Photothermal Catalyst for Efficient Photoreforming of Waste Plastic

The green circular utilization of waste plastics is crucial for environmental protection. Converting waste plastics into H₂ fuel and valuable chemicals by utilization of the solar spectrum is highly attractive. Herein, a photothermal catalyst composed of metallic NiCo₂S₄ and semiconductor Zn_xCd_1-xS (NCS-ZCS) materials is rationally designed. The photogenerated electrons are shown to flow from Zn_xCd_1-xS to NiCo₂S₄ and are excited into hot electrons via the localized surface plasmon resonance effect, promoting H₂ evolution. The holes on Zn_xCd_1-xS serve as the oxidation active species for efficiently converting waste plastic into value-added chemicals. Systematic studies show that the photoreforming process can be enhanced with a photothermal effect from NiCo₂S₄. Theoretical calculations confirmed experimental results. Under visible to infrared irradiation, H₂ evolution rates of 57.0 and 106.0 mmol·g_cat^-1·h^-1 along with the yields of value-added chemicals of 39.18 and 206.05 μmol mL^-1 in polyethylene terephthalate and polylactic acid substrates are achieved.