Xi-Lin Wu

Solar‐driven depolymerization of poly(lactic acid) (PLA) into its lactic acid monomer offers an attractive route to plastic recycling coupled with green hydrogen (H ₂ ) production. However, simultaneously achieving high activity and product selectivity remains difficult because of inefficient charge utilization and uncontrolled oxidation pathways. Here, we fabricated cadmium sulfide (CdS) nanorods decorated with atomically dispersed Ni─S ₄ sites that drive selective photocatalytic PLA depolymerization coupled with efficient H ₂ evolution without any sacrificial reagent. The Ni─S ₄ coordination reconstructs the surface electronic structure of CdS, generating interfacial polarization and directing charge separation with markedly prolonged lifetimes for surface redox reactions. Specifically, this redistribution directs photogenerated electrons to proton reduction and localizes holes at the Ni─S ₄ sites, which selectively activate the ester carbonyl for hydroxide‐assisted cleavage while suppressing deeper oxidation. As a result, NiSAs/CdS delivers a H ₂ production rate of 41.74 mmol g ⁻¹ h ⁻¹ while selectively converting PLA into lactic acid, with no detectable accumulation of common over‐oxidation byproducts such as pyruvate or acetate. These findings establish a charge‐coupled pathway that couples selective plastic depolymerization with solar‐driven H ₂ generation and point to a viable strategy for sustainable plastic upcycling.

Achieving scalable fabrication of robust and uniform single‐atom catalyst‐based gas‐diffusion electrodes (SAC‐GDEs) remains challenging. Here, a universal one‐step soot‐deposition route was developed to convert various metal‐containing paraffins into conformal single‐atom catalyst (SAC) coatings on diverse electrodes (1D fibers, 2D plates, and 3D foams). The process provides multiscale control, from precursor‐defined molecular coordination to micropore wettability and macroscopic geometry, to collectively engineer hierarchical coating films that couple intensified mass transfer and high intrinsic catalytic activity for efficient H ₂ O ₂ electrosynthesis. As a device‐level demonstration, Pd‐SAC‐GDE delivers pH‐universal H ₂ O ₂ production under an industrial‐level current (500 mA cm ⁻² ) for 100 h, achieving a record‐high H ₂ O ₂ yield of 16.9 mol g ⁻¹ h ⁻¹ . A tip‐enhanced mechanism was proposed based on constant‐potential calculations. The results reveal that the curvature‐enhanced localized electric field promotes O ₂ polarization and activation at the Pd‐O ₃ sites, thereby facilitating both ^* OOH generation and adsorption and ultimately leading to highly selective H ₂ O ₂ production. This facile, broadly applicable fabrication strategy significantly advances the scalable manufacture of SAC‐coated GDEs for environmental and sustainable catalysis.

This review systematically summarizes the fabrication, advanced characterization methods, regulation strategies, and applications of single-atom photocatalysts in the fields of environmental remediation and energy conversion.