Acknowledgements p The authors gratefully acknowledge the financially support by the Natural Science Foundation of China as general projects (grant Nos. 22076082 and 21872102, 21874099, 22176140), Natural Science Foundation of Tianjin City of China (grant No. 19YFZCSF00740 and 20YFZCSN01070), Frontiers Science Center for New Organic Matter (grant No. 63181206) and Tianjin Research Innovation Project for

Red phosphorus (RP) has recently attracted much attention in photocatalysis for its low cost, environmental benign and optical properties. However, its photocatalytic activity is still restricted since the low-charge carrier mobility and the high water-solubility. Herein, RP-S-12 h (Combination of RP nanosheet (NS) and bulk RP structure) was prepared by hydrothermal method. Results showed that the multiple reactive active sites, the energy level matching, the emergence of intermediate state and the internal unequal potential for RP-S-12 h ensured higher charge density and efficient carrier transport, improving the photocatalytic activity and stability, emphasizing the role of multiple interfacial effects. The optimum hydrogen evolution rate was 0.33 mmol g-1 h-1, and the quantum efficiency at 420 nm is 0.45%. In addition, RP-S-12 h could completely degrade 50 ppm MO in 12 min. This study provides a novel insight into the interface design of metal-free photocatalyst for environmental remediation.

Automated summary

Red phosphorus (RP) has been attracting attention in photocatalysis due to its low cost, environmental friendliness, and optical properties. A combination of RP nanosheet (NS) and bulk RP structure (RP-S-12 h) was prepared and demonstrated to have higher charge density and efficient carrier transport, resulting in improved photocatalytic activity and stability. The optimized hydrogen evolution rate was 0.33 mmol g-1 h-1 and the quantum efficiency at 420 nm was 0.45%. RP-S-12 h also showed complete degradation of 50 ppm MO in 12 minutes, highlighting its potential in environmental remediation.