Solar-light-driven CO₂ reduction CO to CH₄ and C₂H₆ is a complex process involving multiple elementary reactions and energy barriers. Therefore, achieving high CH₄ activity and selectivity remains a significant challenge. Here, we integrate bifunctional Cu₂O and Cu-MOF (MOF = metal-organic framework) core–shell co-catalysts (Cu₂O@Cu-MOF) with semiconductor TiO₂. Experiments and theoretical calculations demonstrate that Cu₂O (Cu⁺ facilitates charge separation) and Cu-MOF (Cu²⁺ improves the CO₂ adsorption and activation) in the core–shell structure have a synergistic effect on photocatalytic CO₂ reduction, reducing the formation barrier of the key intermediate ^⋆COOH and ^⋆CHO. The photocatalyst exhibits high CH₄ yield (366.0 µmol·g⁻¹·h⁻¹), efficient electron transfer (3283 µmol·g⁻¹·h⁻¹) and hydrocarbon selectivity (95.5%), which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO₂ reduction reaction. This work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.

The application of functional nanomaterials in cancer therapy has become a new developing trend due of their unique size-dependent physicochemical performance. In this study, CuS nanoprisms were fabricated via a seed-mediated growth method. The as-prepared CuS nanoprisms possessed a more intense near-infrared absorption at 1184 nm compared with other morphologies. CuS nanoprisms were modified with a polypyrrole (PPy) shell on the surface through oxidative polymerization. The PPy shell efficiently decreased the nanocomposite cytotoxicity and increased the biocompatibility. Based on the excellent photothermal conversion performance of CuS-PPy nanoprisms, the cancer cells in vitro could be killed effectively and the tumor in vivo could be cured through photothermal therapy. This indicated that CuS-PPy nanoprisms are able to be used as an efficient theranostic agent for tumor photothermal therapy in the future.