The Frontier of Tungsten Oxide Nanostructures in Electronic Applications

Electrochromic (EC) glazing has garnered significant attention recently as a crucial solution for enhancing energy efficiency in future construction and automotive sectors. EC glazing could significantly reduce the energy usage of buildings compared to traditional blinds and glazing. Despite their commercial availability, several challenges remain, including issues with switching time, leakage of electrolytes, production costs, etc. Consequently, these areas demand more attention and further studies. Among inorganic-based EC materials, tungsten oxide nanostructures are essential due to its outstanding advantages such as low voltage demand, high coloration coefficient, large optical modulation range, and stability. This review will summarize the principal design and mechanism of EC device fabrication. It will highlight the current gaps in understanding the mechanism of EC theory, discuss the progress in material development for EC glazing, including various solutions for improving EC materials, and finally, introduce the latest advancements in photo-EC devices that integrate photovoltaic and EC technologies

Recent Progress in Multifunctional Graphene-Based Nanocomposites for Photocatalysis and Electrocatalysis Application

The global energy shortage and environmental degradation are two major issues of concern in today’s society. The production of renewable energy and the treatment of pollutants are currently the mainstream research directions in the field of photocatalysis. In addition, over the last decade or so, graphene (GR) has been widely used in photocatalysis due to its unique physical and chemical properties, such as its large light-absorption range, high adsorption capacity, large specific surface area, and excellent electronic conductivity. Here, we first introduce the unique properties of graphene, such as its high specific surface area, chemical stability, etc. Then, the basic principles of photocatalytic hydrolysis, pollutant degradation, and the photocatalytic reduction of CO2 are summarized. We then give an overview of the optimization strategies for graphene-based photocatalysis and the latest advances in its application. Finally, we present challenges and perspectives for graphene-based applications in this field in light of recent developments

Recent Progress in Graphene-Based Electrocatalysts for Hydrogen Evolution Reaction

Hydrogen is regarded as a key renewable energy source to meet future energy demands. Moreover, graphene and its derivatives have many advantages, including high electronic conductivity, controllable morphology, and eco-friendliness, etc., which show great promise for electrocatalytic splitting of water to produce hydrogen. This review article highlights recent advances in the synthesis and the applications of graphene-based supported electrocatalysts in hydrogen evolution reaction (HER). Herein, powder-based and self-supporting three-dimensional (3D) electrocatalysts with doped or undoped heteroatom graphene are highlighted. Quantum dot catalysts such as carbon quantum dots, graphene quantum dots, and fullerenes are also included. Different strategies to tune and improve the structural properties and performance of HER electrocatalysts by defect engineering through synthetic approaches are discussed. The relationship between each graphene-based HER electrocatalyst is highlighted. Apart from HER electrocatalysis, the latest advances in water electrolysis by bifunctional oxygen evolution reaction (OER) and HER performed by multi-doped graphene-based electrocatalysts are also considered. This comprehensive review identifies rational strategies to direct the design and synthesis of high-performance graphene-based electrocatalysts for green and sustainable applications

Implanting MnO2 into Hexagonal Boron Nitride as Nanoadditives for Enhancing Tribological Performance

Hexagonal boron nitride nanosheets (h-BNNs) show great potential in the field of tribology due to their typical two-dimensional layered structure and are essential for replacing conventional sulfur/phosphate-containing additives. However, the large particle size and poor dispersion of h-BNs seriously restrict their green lubrication application. In this paper, MnO2@h-BNNs nanocomposites were successfully prepared by ultrasonically exfoliating a hydrothermal method. The tribological properties of MnO2@h-BNNs nanocomposites as lubricant additives in poly-alpha-olefin oil (PAO) were investigated. The results show the oil dispersed with 0.25 wt% MnO2@h-BNNs had the best friction reduction and antiwear effect with 42% and 11.2% reduction, respectively, compared with the plain oil. Through further wear surface analyzing, we verified the antiwear mechanism of additives in filling the micropits and grooves on the wear surface and forming a friction protection film including Fe2O3, MnO2, and BN on the wear surface, avoiding direct contact between the friction subsets. This can provide ideas for other lubricating oil additives