Deep UV photoluminescence and Hall-effect measurements were employed to characterize Mg-doped AlN grown by metal organic chemical vapor deposition. A strong correlation between the optical and electrical properties was identified and utilized for material and p-type conductivity optimization. An impurity emission peak at 4.7eV, attributed to the transition of electrons bound to triply charged nitrogen vacancies to neutral magnesium impurities, was observed in highly resistive epilayers. Improved conductivity was obtained by suppressing the intensity of the 4.7eV emission line. Mg-doped AlN epilayers with improved conductivities predominantly emit the acceptor-bound exciton transition at 5.94eV. From the Hall-effect measurements performed at elevated temperatures, the activation energy of Mg in AlN was measured to be about 0.5eV, which is consistent with the value obtained from previous optical measurements. Energy levels of nitrogen vacancies and Mg acceptors in Mg-doped AlN have been constructed.

Antibiotics are chemical compounds that are used to kill or prevent bacterial growth. They are used in different fields, such as the medical field, agriculture, and veterinary. Antibiotics end up in wastewater, which causes the threat of developing antibacterial resistance; therefore, antibiotics must be eliminated from wastewater. Different conventional elimination methods are limited due to their high cost and effort, or incomplete elimination. Semiconductor-assisted photocatalysis arises as an effective elimination method for different organic wastes including antibiotics. A variety of semiconducting materials were tested to eliminate antibiotics from wastewater; nevertheless, research is still ongoing due to some limitations. This review summarizes the recent studies regarding semiconducting material modifications for antibiotic degradation using visible light irradiation.

The energy from fossil fuels has been recognized as a main factor of global warming and environmental pollution. Therefore, there is an urgent need to replace fossil fuels with clean, cost-effective, long-lasting, and environmentally friendly fuel to solve the future energy crisis of the world. Therefore, the development of clean, sustainable, and renewable energy sources is a prime concern. In this regard, solar energy-driven hydrogen production is considered as an overriding opening for renewable and green energy by virtue of its high energy efficiency, high energy density, and non-toxicity along with zero emissions. Water splitting is a promising technology for producing hydrogen, which represents a potentially and environmentally clean fuel. Water splitting is a widely known process for hydrogen production using different techniques and materials. Among different techniques of water splitting, electrocatalytic and photocatalytic water splitting using semiconductor materials have been considered as the most scalable and cost-effective approaches for the commercial production of sustainable hydrogen. In order to achieve a high yield of hydrogen from these processes, obtaining a suitable, efficient, and stable catalyst is a significant factor. Among the different types of semiconductor catalysts, tungsten disulfide (WS2) has been widely utilized as a catalytic active material for the water-splitting process, owing to its layered 2D structure and its interesting chemical, physical, and structural properties. However, WS2 suffers from some disadvantages that limit its performance in catalytic water splitting. Among the various techniques and strategies that have been constructed to overcome the limitations of WS2 is heterostructure construction. In this process, WS2 is coupled with another semiconducting material in order to facilitate the charge transfer and prevent the charge recombination, which will enhance the catalytic performance. This review aims to summarize the recent studies and findings on WS2 and its heterostructures as a catalyst in the electrocatalytic and photocatalytic water-splitting processes.

We investigated the fabrication of Co-doped BiVO4 (Bi1−xCoxVO4+δ, 0.05 < x < 0.5) by the substitution of Co ions for Bi sites in BiVO4.

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Water pollution is one of the most serious environmental issues globally due to its harmful consequences on the ecosystem and public health. Various technologies have been developed for water treatment such as photocatalysis, which has recently drawn scientists’ attention. Photocatalytic techniques using semiconductors have shown an efficient removal of various water contaminants during water treatment as well as cost effectivity and low energy consumption. Tungsten disulfide (WS2) is among the promising Transition Metal Dichalcogenides (TMDs) photocatalysts, as it has an exceptional nanostructure and special properties including high surface area and high carrier mobility. It is usually synthesized via hydrothermal technique, chemical vapor deposition (CVD), and liquid-phase exfoliation (LPE) to obtain a wide variety of nanostructures such as nanosheets and nanorods. Most common examples of water pollutants that can be removed efficiently by WS2-based nanomaterials through semiconductor photocatalytic techniques are organic contaminants, pharmaceuticals, heavy metals, and infectious microorganisms. This review summarizes the most recent work on employing WS2-based nanomaterials for different photocatalytic water treatment processes.