Nano Metal-Containing Photocatalysts for the Removal of Volatile Organic Compounds: Doping, Performance, and Mechanisms

Abstract

Volatile organic compounds (VOCs) in indoor air are considered a major threat to human health and environmental safety. The development of applicable technologies for the removal of VOCs is urgently needed. Nowadays, photocatalytic oxidation (PCO) based on metal-containing photocatalysts has been regarded as a promising method. However, unmodified photocatalysts are generally limited in applications because of the narrow light response range and high recombination rate of photo-generated carriers. As a result, nano metal-containing photocatalysts doped with elements or other materials have attracted much attention from researchers and has developed over the past few decades. In addition, different doping types cause different levels of catalyst performance, and the mechanism for performance improving is also different. However, there are few reviews focusing on this aspect, which is really important for catalyst design and application. This work aims to give a comprehensive overview of nano metal-containing photocatalysts with different doping types for the removal of VOCs in an indoor environment. First, the undoped photocatalysts and the basic mechanism of PCO is introduced. Then, the application of metal doping, non-metal doping, co-doping, and other material doping in synthetic metal-containing photocatalysts are discussed and compared, respectively, and the synthesis methods, removal efficiency, and mechanisms are further investigated. Finally, a development trend for using nano metal-containing photocatalysts for the removal of VOCs in the future is proposed. This work provides a meaningful reference for selecting effective strategies to develop novel photocatalysts for the removal of VOCs in the future.

Advancements in Doping Strategies for Enhanced Photocatalysts and Adsorbents in Environmental Remediation

“…In volatile organic compound (VOC) degradation, metal/metal co-dopants, such as silver and vanadium co-doping in TiO 2 nanoparticles, had served a dual role: ensuring uniform metal dispersion on the photocatalyst and creating oxygen vacancies. In the case of non-metal co-dopants, research had demonstrated that co-doping with carbon and nitrogen in TiO 2 can synergistically enhance VOC degradation without altering the catalyst's morphology [142]. However, it is important to note that co-doping may also present challenges, including the potential for enhanced electron-hole pair recombination and nanoparticle shielding effects.…”

Recent Advances in MXenes Based Composites as Photocatalysts: Synthesis, Properties and Photocatalytic Removal of Organic Contaminants from Wastewater

“…Additionally, the stability and recyclability of photocatalysts, as well as the potential toxicity of nanomaterials, need to be carefully addressed and evaluated. Nonetheless, research in the field of photocatalytic degradation continues to advance, focusing on the development of efficient and cost‐effective photocatalytic materials, exploration of alternative light sources, and the optimization of reaction conditions [47–49] . These efforts aim to overcome the drawbacks and limitations of existing treatment methods, providing a sustainable and effective solution for the removal of dyes and other pollutants from wastewater.…”