Photocatalytic wastewater treatment technology has been proposed for more than 30 years, but it is still seldom used in industry. The lack of research on high-performance and cost-effective photocatalytic wastewater treatment reactors (PWTRs) may be one of the major reasons limiting the industrial application of photocatalytic technology. To accelerate the realization of industrial application, this review emphasizes the importance of increased research on PWTRs. In this review, we analyze the role of photocatalytic technology in wastewater treatment, followed by a comprehensive discussion of PWTR design from multiple perspectives, including photocatalyst selection, loading and recovery method of photocatalysts within the reactor, light source design, and reaction conditions control. Additionally, we consider the cost of reactor design. Finally, we summarize the optimization strategy of PWTRs and the criteria for evaluating photocatalytic performance. The main innovation of this review lies in a comprehensive analysis of PWTR design, with a focus on cost-effective and high-performance solutions to promote the industrial use of photocatalytic technology.

Photocatalysis materials have gained significant attention as a powerful tool for environmental remediation and green energy generation, due to their remarkable ability to convert solar energy into chemical energy efficiently. Additionally, photocatalysis also plays a significant role in the medical realm, facilitating advancements in drug synthesis. However, the wavelengths of photocatalysis light normally focus on UV light, which is usually generated by higher energy. In recent years, the spotlight has shifted towards visible-light photocatalysis as a promising green and sustainable alternative due to the increasing concerns about environmental challenges and energy crises. This review focuses on the recent advancements in visible-light photocatalysis materials and emphasizes the diverse types of photocatalytic materials and their impactful applications in environmental remediation, organic synthesis chemistry, and energy conversion. Furthermore, the prevailing challenges and potential solutions in visible-light photocatalysis materials are also summarized to provide valuable insights for the further development and optimization of photocatalysis. Received: 25 April 2024 | Revised: 24 July 2024 | Accepted: 10 January 2025 Conflicts of Interest Jun Zou is an Editorial Board Member for Journal of Optics and Photonics Research and was not involved in the editorial review or the decision to publish this article. The authors declare that they have no conflicts of interest to this work. Data Availability Statement Data are available from the corresponding author upon reasonable request. Author Contribution Statement Xiaoyang Li: Investigation, Resources, Writing – original draft. Sihan Lin: Investigation. Rongrong Hu: Conceptualization, Investigation, Resources, Writing – review & editing, Supervision, Funding acquisition. Pan Liang: Investigation. Qiaoyun Wu: Investigation, Resources. Bobo Yang: Investigation. Shengquan Lin: Investigation. Quanlong Xu: Investigation. Junnan Mei: Investigation. Jun Zou: Conceptualization, Investigation, Supervision, Funding acquisition.

This study proposes a particle swarm optimization (PSO)-based method for enhancing the irradiance uniformity of light emitting diode (LED) arrays in parallel photoreactors. We construct a spatial irradiance model, validating its accuracy with near-field optical test data and optical simulation results. An evaluation function for irradiance uniformity guides the iterative optimization of the LED arrangement, taking into consideration practical constraints such as chip size, heat dissipation, and circuit board wiring. The optimized LED array demonstrated a significant improvement in irradiance uniformity, increasing from 75.27% to 95.61%. This showcases the feasibility and effectiveness of our PSO-based method for practical applications in optimizing LED arrays.