image: Heterogeneous photocatalysis has garnered extensive attention in the field of environmental remediation. Recently, pollutants in the natural environment have gradually increased and become complex. Here, recent studies of the potential semiconductors and varies modification strategies for environmental photocatalysis are systematically presented. This review may provide reference directions toward understanding, researching, and designing photocatalytic remediation systems for various environmental pollutants. view more
Credit: Chinese Journal of Catalysis
In recent years, the fast-growing global population and the rapid development of industries have triggered an energy crisis and environmental pollution and have considerably influenced the health of humans and the sustainable development of the environment. Therefore, environmental protection and pollutant removal technologies have gradually become the most important topics. Heterogeneous photocatalysis was first discovered by Fujishima et al. in 1972 during the splitting of H2O in a photoelectrochemical cell comprising a monocrystalline TiO2 electrode. Heterogeneous photocatalysis, an environmentally friendly advanced oxidation process, has slowly provided the prelude for environmental remediation.
Heterogeneous photocatalytic reactions have many advantages, such as (1) the use of solar light, which is a sustainable resource; (2) a quick reaction rate and low energy consumption of heterogeneous photocatalytic oxidation; (3) milder reaction conditions than those of traditional thermal catalysis, when compared with conventional treatment technologies (including adsorption, membrane separation, chemical sedimentation, and bioprocesses). Thus, the application of solar energy to eliminate several environmental pollutants is of major significance from the perspective of energy conservation and environmental remediation. Consequently, to date, thousands of studies have been reported on the photocatalytic treatment of various pollutants, and new studies are being increasingly conducted in this regard. The number of journal papers on photocatalytic degradation has significantly increased over the past 20 years. Notably, more than 9000 journal papers have been published on the photocatalytic degradation of several pollutants in 2020. Note that in addition to the photocatalytic degradation of pollutants in the H2O environment, many pollutants in the soil and the atmosphere can be efficiently removed by heterogeneous photocatalysis. The photocatalytic removal of various potential pollutants, for example, nitrogen oxides (NOx), heavy metal ions, persistent organic pollutants, plastic waste, pathogenic bacteria, and S-containing fossil fuels, has also substantially increased in the past 20 years.
Recently, researchers have developed numerous semiconductors, such as metal oxide semiconductors, Ag or Bi-based semiconductors, metal-free and polymer semiconductors, metal-organic frameworks (MOFs), and metal sulfide semiconductors, for the elimination of different environmental pollutants. Additionally, various modification strategies, including the construction of heterojunction systems, defect engineering, and cocatalyst loading, have been proposed. Moreover, many reviews have promoted the use of environmental photocatalysis for the removal of numerous pollutants. However, there are still substantial challenges, such as the high cost of semiconductors, lower solar energy utilization rate, and rapid recombination of photogenerated e--h+ pairs, that hinder the practical large-scale environmental applications of this technology. Other significant knowledge gaps are that the mechanism and comprehensive kinetics and thermodynamics thermodynamic of photocatalysis are yet to be completely understood. Consequently, it is necessary to extensively review the applications of semiconductor modification strategies in photocatalysis for the elimination of various environmental pollutants.
Recently, a review led by Prof. Pengwei Huo from Jiangsu University and Prof. Xin Li from South China Agricultural University, China started with a discussion of the fundamentals, including the fundamental principles of environmental photocatalysis, reactive oxidation species, mechanism of environmental photocatalysis, and uncertainties and challenges in environmental photocatalysis. Subsequently, potential semiconductors and their modification strategies for environmental remediation are discussed. Finally, remarks and perspectives on the development of semiconductors for environmental photocatalysis are provided. This review may offer some useful guidelines for the identification and application of heterogeneous photocatalysts in the field of environmental photocatalysis. This review was published in Chinese Journal of Catalysis (https://doi.org/10.1016/S1872-2067(21)63910-4).
###
About the Journal
Chinese Journal of Catalysis is co-sponsored by Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Chinese Chemical Society, and it is currently published by Elsevier group. This monthly journal publishes in English timely contributions of original and rigorously reviewed manuscripts covering all areas of catalysis. The journal publishes Reviews, Accounts, Communications, Articles, Highlights, Perspectives, and Viewpoints of highly scientific values that help understanding and defining of new concepts in both fundamental issues and practical applications of catalysis. Chinese Journal of Catalysis ranks among the top six journals in Applied Chemistry with a current SCI impact factor of 8.271. The Editors-in-Chief are Profs. Can Li and Tao Zhang.
At Elsevier http://www.journals.elsevier.com/chinese-journal-of-catalysis
Manuscript submission https://mc03.manuscriptcentral.com/cjcatal
Journal
Chinese Journal of Catalysis
Article Publication Date
17-Jan-2022