Red phosphorus (RP), as a promising non-metallic photocatalyst, has garnered considerable attention due to its unique structural characteristics and exceptional optoelectronic properties. While previous reviews have explored RP-based photocatalysis, recent advancements in fabrication strategies, characterization techniques, and theoretical modeling have significantly reshaped the design, synthesis, and optimization of these materials. This review provides a comprehensive and critical evaluation of the latest progress in RP-based photocatalysts over the past five years, with a particular focus on strategies aimed at enhancing light harvesting capabilities, improving the separation and transport of photogenerated charge carriers, and ensuring long-term stability. Particular emphasis is placed on the role of innovative in-situ characterization techniques and density functional theory (DFT) simulations in elucidating the underlying photocatalytic mechanism across diverse applications, including photocatalytic hydrogen evolution, CO₂ reduction, bacterial disinfection and organic pollutant degradation. Finally, this review highlights emerging challenges and forward-looking strategies to further boost the photocatalytic performance of RP-based systems, offering valuable insights for the rational design of next-generation non-metallic photocatalysts.

The construction of S-scheme heterojunction represents a simple yet effective strategy for enhancing photogenerated charge carrier separation and optimizing the reduction and oxidation capability of the photocatalytic system. However, precise tuning of the internal electric field for optimizing charge carrier migration across the heterojunction remains challenging. Herein, we present a novel defect engineering approach to modulate the potential barrier in S-scheme heterojunctions through strategic oxygen vacancy introduction. Specifically, we first selectively introduce oxygen vacancies on Bi₂WO₆, followed by coupling with g-C₃N₄ to form oxygen-deficient Bi₂WO₆/g-C₃N₄ (OVs-BWO-CN) S-scheme heterojunction. Surprisingly, the selective oxygen vacancy engineering on OVs-BWO cannot only preserve the features of common oxygen vacancies, but also shrink the potential barrier formed between OVs-BWO and CN. This reduction in potential barrier facilitates enhanced charge carrier migration across the heterojunction interface. As a direct consequence of this optimized charge transfer, the CN/OVs-BWO heterojunction demonstrates exceptional photocatalytic CO₂ conversion performance, reaching a CO production rate of 48.65 μmol h⁻¹ g⁻¹. Such a work on selective oxygen vacancy engineering for optimizing potential barrier can provide important guidelines for photocatalysis.

The electrochemical conversion and storage of renewable energy presents substantial potential as a sustainable alternative to conventional fossil fuel energy systems. This approach not only supports the transition to cleaner energy but also enhances energy security and promotes environmental sustainability. Central to this field is electrocatalysis, which facilitates the transformation of reactants into high-value chemicals and relies on the efficiency of catalytic processes. The increasing interest in electrocatalytic activity is simulated by advances in catalyst design and mechanistic understanding. However, traditional electrochemical techniques often fall short in uncovering the distinct properties of nanomaterials. Recent advancements in physical nanoelectronic devices indicate that the application of small-scale devices in electrocatalysis offers a promising and innovative solution. These innovative devices enable precise electrochemical investigations by employing individual nanowires or nanosheets as working electrodes, thereby providing multi-dimensional insights into electrochemical interfaces. This review presents recent advancements in on-chip microdevices, emphasizing their significant developments in energy conversion and storage technologies. It highlights the critical role of micro-devices in fostering future innovations and enhancing their applications within the energy sector.