Enhanced Charge Transfer Dynamics in a NiCo2S4–ZnxCd1–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 ZnxCd1–xS (NCS–ZCS) materials is rationally designed. The photogenerated electrons are shown to flow from ZnxCd1–xS to NiCo2S4 and are excited into hot electrons via the localized surface plasmon resonance effect, promoting H2 evolution. The holes on ZnxCd1–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·gcat–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.