Activated carbon as a catalyst to promote the reactivity of hydroquinone in skin whitening cosmetics

This review paper explores the application of activated carbons (ACs) in skin whitening cosmetics and their basic characteristics as a catalyst. Firstly, the physical and chemical properties of ACs, as well as their theoretical basis as catalysts, were introduced. Subsequently, a detailed analysis was conducted on the mechanism of ACs in promoting the reactivity of hydroquinone (HQ), including physical adsorption, chemical interactions, and the role of surface functional groups. The paper compared the performance of different types of ACs such as wood-based, coconut shell-based, coal-based, and supported ACs in catalytic reactions and compared them with other catalysts. In order to optimize the catalytic performance of ACs, strategies for changing preparation methods and conditions were explored, such as physical and chemical activation methods, microwave-assisted preparation, and adjustment of carbonization temperature and time. In addition, the paper also discusses the potential advantages of ACs in whitening cosmetics, such as improving the effectiveness of whitening ingredients and enhancing product safety, as well as the challenges faced, including stability issues and possible side effects. The future development directions include innovation and improvement of AC-materials, in-depth research on their interaction with the skin, development of composite materials, and the application of green chemistry in the preparation of ACs. Finally, the paper explores the binding mechanism of ACs with other whitening agents and its limitations in formulation and environment and summarizes the application prospects of ACs in cosmetics.