Liu Xijun¹， Pei Xinxiang¹， Ding Junyang¹， Yang Miaosen²

1.School of Resources， Environment and Materials， Guangxi University， Nanning 530001， China； 2.School of Chemical Engineering， Northeast Electric Power University， Jilin 132012， China

Abstract

Significance As the threat posed by organic small-molecule pollutants in water to the ecological environment and human health continues to intensify， the development of efficient and stable advanced oxidation technologies has become an urgent need in the environmental field. This paper reviews recent research progress on carbon-based single-atom catalysts （SACs） in advanced oxidation systems for the degradation of organic small-molecule pollutants in water， and analyzes their catalytic active centers and reaction mechanisms， aiming to provide a basis for the rational design and preparation of efficient catalytic materials for water treatment.

Progress Given their strong oxidizing capacity， high efficiency， rapid reaction rate， wide application range， and good environmental compatibility， advanced oxidation technologies have received considerable attention in the field of wastewater treatment. Specifically， advanced oxidation technologies can effectively mineralize or transform recalcitrant organic pollutants in water by generating highly reactive radicals （e.g.， hydroxyl radicals ·OH， sulfate radical ·SO₄^-）， demonstrating significant advantages particularly in the treatment of trace toxic and harmful substances such as antibiotics， pesticides， and dyes. This study first systematically reviews various types of advanced oxidation technologies， including photochemical oxidation （using ultraviolet or visible light to excite oxidants or semiconductor materials）， catalytic wet air oxidation （accelerating oxidation reactions under high-temperature and high-pressure conditions with the aid of catalysts）， sonochemical oxidation （generating localized high temperature and high pressure via the ultrasonic cavitation effect to initiate radical reactions）， ozone oxidation （directly or indirectly utilizing ozone molecules and the reactive oxygen species generated from their decomposition）， electrochemical oxidation （achieving pollutant degradation through direct electron transfer at the electrode surface or indirect generation of active chlorine/hydroxyl radicals）， homogeneous Fenton oxidation （e.g.， Fe²⁺ catalyzing H₂O₂ to generate ·OH）， heterogeneous Fenton-like oxidation （immobilizing iron-based or other transition metals on solid supports to broaden the pH applicability range and improve catalyst recyclability）， photo-Fenton oxidation （introducing a light source to promote the reduction of Fe³⁺ to Fe²⁺， thereby enhancing the decomposition efficiency of H₂O₂）， and electro-Fenton oxidation （generating H₂O₂ via in-situ reduction of O₂ at the cathode， which synergistically produces ·OH with externally added Fe²⁺ or iron-based materials）. The aforementioned technologies each possess distinct characteristics in terms of mechanism， operating conditions， energy consumption， and applicable pollutant types， and there is an urgent need for systematic comparison and summarization. Meanwhile， given that carbon-based SACs exhibit an atomic utilization rate approaching 100%， possess well-defined and designable active site structures， and allow fine-tuning of their electronic properties by regulating the coordination environment （e.g.， N， O， S doping） and carbon support defects， they demonstrate significant advantages in advanced oxidation technologies. Consequently， carbon-based SACs can efficiently activate oxidants such as H₂O₂， persulfates， and O₃， greatly enhancing the generation efficiency of reactive oxygen species， thereby achieving the efficient degradation and even mineralization of trace organic small-molecule pollutants in water （such as phenols， anilines， and pharmaceuticals）. Therefore， this paper focuses on the application of representative carbon-based single-atom catalysts in the catalytic degradation of organic small-molecule pollutants， specifically including single-metal-site catalysts （e.g.， Cu， Ni， Mn， Co， Fe） and bimetallic-site catalysts （e.g.， FeCu， FeCo， FeNi， CoNi）， aiming to provide new insights and feasible solutions for water pollution prevention and sustainable development.

Conclusions and Prospects In recent years， carbon-based SACs demonstrate significant advantages in the catalytic degradation of organic small-molecule pollutants in water， due to their high atomic utilization， uniform active sites， and tunable electronic structure. Specifically， through precise design of active sites and support regulation， SACs can efficiently activate oxidants such as persulfates and H₂O₂， thereby enabling the rapid degradation of various organic pollutants and offering a new direction for efficient water treatment technologies. Although SACs exhibit excellent catalytic performance in advanced oxidation processes at the laboratory scale， they still face numerous severe challenges in practical water treatment applications. First， the difficulty in large-scale preparation is one of the core bottlenecks currently limiting the industrialization of SACs， and there is an urgent need to develop continuous and green synthesis routes suitable for industrial scale-up. Second， structural stability issues are equally prominent. Under long-term continuous operation or real complex water quality conditions， single-atom sites are prone to deactivation due to metal agglomeration， leaching， or poisoning， resulting in a significant shortening of catalyst lifespan. To overcome the above challenges， future research should achieve breakthroughs in the following aspects. First， the deep integration of in situ characterization and theoretical calculations should be further strengthened to reveal the mechanism of action of SACs under real reaction conditions at the atomic and molecular levels， thereby providing theoretical guidance for the rational design of highly stable and active catalysts. Second， efforts should be made to develop new strategies for the low-cost and scalable synthesis of SACs. Third， process integration and reactor innovation should be vigorously promoted to simulate the operating conditions of actual wastewater treatment plants. Through the above multidisciplinary and engineering efforts， it is expected that carbon-based SACs will progress from laboratory research to practical wastewater treatment applications， providing robust technical support for the improvement of water environment quality and sustainable development.

Keywords: carbon⁃based; single⁃atom catalyst; organic small⁃molecule pollutant; advanced oxidation technology

Get Citation：Liu Xijun， Pei Xinxiang， Ding Junyang， et al. Research progress on carbon⁃based single⁃atom catalysts for catalytic degradation of organic small-molecule pollutants in water［J］. China Powder Science and Technology， 2026， 32（5）： 1-14.

Received：2026-03-04，Revised： 2026-04-16，Online： 2026-07-23.

Funding：The research was supported by the National Natural Science Foundation of China (Grant No. 22469002) and the Outstanding Young Scientist Program of the Guangxi Natural Science Foundation (Grant No. 2024GXNSFFA010008).

DOI：10.13732/j.issn.1008-5548.2026.05.005

CLC No.：TB4；X52

Type Code：A

Serial No.：1008-5548（2026）05-0001-14