NING Kuo，LI Jing，YAN Liangguo，SONG Wen

School of Water Conservancy and Environment， University of Jinan，Jinan 250022，China

Abstract

Significance Photothermal conversion is a novel water treatment technology developed in recent years. It utilizes photothermal materials to convert solar energy into thermal energy for efficient water evaporation. If wastewater contains non-degradable or toxic organic compounds，advanced oxidation processes can degrade organic pollutants by generating highly oxidative free radicals or non-radical species. Combining photothermal conversion with advanced oxidation processes can leverage both their advantages，achieving water evaporation and degradation of pollutants simultaneously.Nanomaterials， with their unique physical，chemical，and nanoscale properties， can serve as catalysts， adsorbents，or carriers in water treatment methods，including advanced oxidation processes， adsorptive coagulation techniques，and biological water treatment systems，providing new materials to address water scarcity and pollution.

Progress Nanomaterials based on photothermal conversion processes primarily include metal（gold，silver，aluminum，copper，palladium，etc.）nanomaterials，carbon nanomaterials（carbon nanotubes，GO，rGO，etc.），and semiconductor nanomaterials （TiO₂，Ti₂O₃，MoS₂，Fe₃O₄，etc.）.Additionally，ceramics，nitrides，and organic polymers such as polypyrrole are also com⁃ monly used as photothermal conversion materials. Nanomaterials based on advanced oxidation processes mainly include photo⁃ catalytic materials（TiO₂，ZnO，CdS，BN，etc.）， Fenton and Fenton-like reaction materials（Fe₃O₄，Fe₂O₃，FeO，etc.），electrocatalytic materials（MnO₂，PbO₂，MoS₂， CoS₂，TiN，graphene，carbon nanotubes），and activated persulfate materials. Nanomaterials with both photothermal conversion and catalytic capabilities include metal oxides（TiO₂，ZnO，Fe₂O₃，CuO），metalorganic framework（MOFs），and composite nanomaterials.

Conclusions and Prospects Photothermal conversion nanomaterials， due to their nanoscale size，large surface area，and strong light absorption capabilities，can achieve efficient photothermal conversion，significantly enhancing water evaporation rate and making water treatment more efficient.The photothermal process has broad applications in seawater desalination， wastewater treatment，power generation，agricultural irrigation， and sterilization.Nanomaterials based on advanced oxidation processes function as catalysts with large surface area and numerous active sites，facilitating the generation of highly reactive radicals（·OH，SO₄^·-，and ∙O₂^-）and non-radical species（¹O₂），thereby capable of decomposing complex organic pollutants into carbon dioxide，water， and harmless or low-toxic intermediates. Nanomaterials based on the photothermal conversion-advanced oxidation process can absorb solar energy and convert it into thermal energy for photothermal conversion，heating molecules to the state of evaporation. It also can serve as catalysts to generate active substances with strong oxidative capacities that disrupt pollutant chemical structures. Moreover，using sunlight and heat generated by the photothermal process can enhance the degradation of pollutants，reducing the energy and costs required for wastewater treatment. Further studies can focus on the development of high-performance nanomaterials， such as improving the stability of MOFs and reducing the use of toxic metal ions to lower potential secondary pollution risks. It is necessary to design more systems based on the photothermal evaporation-advanced oxidation process，such as evaporators，photothermal collection systems， advanced oxidation reactors，etc.，to improve the continuous operation capability of systems and explore new application areas.

Keywords：nanomaterials；photothermal conversion process； advanced oxidation process；water treatment