Highly efficient visible/near-infrared light photocatalytic degradation of antibiotic wastewater over 3D yolk-shell ZnFe2O4 supported 0D carbon dots with up-conversion property

Mechanistic insight into near-infrared light-driven Cu2O/WO2 Ohmic contact photothermal catalysts for high-efficiency antibiotic wastewater purification

Near-infrared (NIR) light-induced photothermal effect is beneficial for accelerating catalytic processes; thus, it is imperative to develop novel photothermal catalysts for promoting practical application. Herein, we synthesized NIR-responsive Cu2O/WO2 Ohmic contact photothermal catalysts through a facile ethylene glycol-assisted liquid-phase reduction method. In this photothermal catalyst, a new-type NIR-responsive Cu2O semiconductor is integrated with an NIR-responsive WO2 semimetal component to form an Ohmic contact, which is more beneficial for simultaneously promoting photocharge separation and enhancing NIR light absorption for a high-efficiency photothermal effect. As expected, the Cu2O/WO2 composite displays higher NIR light-driven photothermal catalytic performance for tetracycline removal from wastewater. Various characterization methods and density functional theory calculations were performed to obtain in-depth mechanistic insights into the NIR light-driven Cu2O/WO2 Ohmic contact photothermal catalysts. Hopefully, this research could provide a useful guideline for researchers focusing on the photothermal engineering of new composite photocatalysts.

A critical review on the environmental applications of carbon dots

The discovery of zero-dimensional carbonaceous nanostructures called carbon dots (CDs) and their unique properties associated with fluorescence, quantum confinement and size effects have intrigued researchers. There has been a substantial increase in the amount of research conducted on the lines of synthesis, characterization, modification, and enhancement of properties by doping or design of composite materials, and a diversification of their applications in sensing, catalysis, optoelectronics, photovoltaics, and imaging, among many others. CDs fulfill the need for inexpensive, simple, and continuous environmental monitoring, detection, and remediation of various contaminants such as metals, dyes, pesticides, antibiotics, and other chemicals. The principles of green chemistry have also prompted researchers to rethink novel modes of nanoparticle synthesis by incorporating naturally available carbon precursors or developing micro reactor-based techniques. Photocatalysis using CDs has introduced the possibility of utilizing light to accelerate redox chemical transformations. This comprehensive review aims to provide the reader with a broader perspective of carbon dots by encapsulating the concepts of synthesis, characterization, applications in contaminant detection and photocatalysis, demerits and research gaps, and potential areas of improvement.