In-situ synthesis of dual Z-scheme heterojunctions of cuprous oxide/layered double hydroxides/nitrogen-rich graphitic carbon nitride for photocatalytic sterilization

Sequential Regulation of Local Reactive Oxygen Species by Ir@Cu/Zn-MOF Nanoparticles for Promoting Infected Wound Healing

Most antimicrobials treat wound infections by an oxidation effect, which is induced by the generation of reactive oxygen species (ROS). However, the potential harm of the prolonged high level of ROS should not be ignored. In this study, we presented a novel cascade-reaction nanoparticle, Ir@Cu/Zn-MOF, to effectively regulate the ROS level throughout the healing progress of the infected wound. The nanoparticles consisted of a copper/zinc-modified metal-organic framework (Cu/Zn-MOF) serving as the external structure and an inner core composed of Ir-PVP NPs, which were achieved through a process known as "bionic mineralization". The released Cu2+ and Zn2+ from the shell structure contributed to the production of ROS, which acted as antimicrobial agents during the initial stage. With the disintegration of the shell, the Ir-PVP NP core was gradually released, exhibiting the property of multiple antioxidant enzyme activities, thereby playing an important role in clearing excessive ROS and alleviating oxidative stress. In a full-layer infected rat wound model, Ir@Cu/Zn-MOF nanoparticles presented exciting performance in promoting wound healing by clearing the bacteria and accelerating neovascularization as well as collagen deposition. This study provided a promising alternative for the repair of infected wounds.

The Application of Mineral Kaolinite for Environment Decontamination: A Review

Kaolinite clay mineral with a layered silicate structure is an abundant resource in China. Due to its advantages of excellent stability, high specific surface area and environmental friendliness, kaolinite is widely used in environment decontamination. By using kaolinite as a carrier, the photocatalytic technology in pure photocatalysts of poor activities, narrow spectral responses, and limited electron transport can be overcome, and the nano-Ag disinfectant’s limitation of the growth and aggregation of nanoparticles is released. Moreover, pure kaolinite used as an adsorbent shows poor surface hydroxyl activity and low cation exchange, leading to the poor adsorption selectivity and easy desorption of heavy metals. Current modification methods including heat treatment, acid modification, metal modification, inorganic salt modification, and organic modification are carried out to obtain better adsorption performance. This review systematically summarizes the application of kaolinite-based nanomaterials in environmental decontamination, such as photocatalytic pollutant degradation and disinfection, nano silver (Ag) disinfection, and heavy metal adsorption. In addition, applications on gas phase pollutant, such as carbon dioxide (CO2), capture and the removal of volatile organic compounds (VOCs) are also discussed. This study is the first comprehensive summary of the application of kaolinite in the environmental field. The review also illustrates the efficiency and mechanisms of coupling naturally/modified kaolinite with nanomaterials, and the limitation of the current use of kaolinite.