Carbon vacancies enriched carbon nitride nanotubes for Pd coordination environment optimization: Highly efficient photocatalytic hydrodechlorination and CO2 cycloaddition

Light-Driven CO2 Fixation into Epoxides Using an Al2O3/CoAl2O4 Composite Photocatalyst

Utilization of carbon dioxide (CO2) as a C1 feedstock to synthesize value-added chemicals using a catalyst made from earth-abundant elements and under mild conditions is a sustainable approach toward carbon neutrality but difficult to achieve. Herein, the CoAl2O4/Al2O3 composite catalyst is developed and used for the light-driven epoxide to value-added cyclic carbonate conversion using CO2. CoAl2O4/Al2O3 composite catalysts (x% Co-Al2O3) are prepared by calcining cobalt-incorporated Al-oxy-hydroxide at 500 °C under an air atmosphere. The composite 15% Co-Al2O3 (57% Al2O3 and 43% CoAl2O4) shows the highest photothermal conversion efficiency (η = 66%) as well as catalytic activity toward CO2 fixation into epoxides to generate cyclic carbonates under 1 atm CO2 pressure and solvent-free conditions (300 W xenon lamp). The catalyst displays good selectivity for the synthesis of a series of cyclic carbonates (>95%) with good yield in the presence of tetra butyl ammonium iodide (TBAI) as a cocatalyst (2 mol % with respect to epoxide). Under the optimized reaction parameters, 15% Co-Al2O3 retains its catalytic activity up to 8 cycles of catalysis without losing its chemical integrity. The reaction mechanism is proposed based on a structure-photothermal conversion-catalytic activity relationship study and a few control experiments. The design and development of a photocatalyst from the earth-abundant Al element under user-friendly conditions make this approach sustainable for the CO2 economy.

Recent advances in the design and preparation of graphitic carbon nitride for photocatalysis

Graphitic carbon nitride (g-C3N4) has recently gained tremendous attention as a promising photocatalyst for environmental and energy-related applications owing to its high thermal and physicochemical stability as well as its suitable band structure. However, bulk g-C3N4, typically synthesized by directly heating N-rich small molecules, often suffers from severe aggregation, a low specific surface area for light harvesting and rapid recombination of photogenerated electron-hole pairs. These factors significantly hinder its photocatalytic efficiency. Consequently, considerable efforts have been devoted to the rational design and synthesis of g-C3N4 with tailored morphologies and controllable electronic and band structures, utilizing both top-down and bottom-up approaches. Thus far, in addition to the conventional and commonly used methods for carbon nitride preparation, new techniques and precursor families are continuously being developed. This review discusses the latest advancements in synthetic approaches for g-C3N4-based materials and provides valuable insights into utilizing these methods to enhance their photocatalytic performance. Finally, the review concludes by presenting an outlook on the future directions and challenges in the development of CN materials for photocatalysis.

Synergistic antibacterial mechanism of silver-copper bimetallic nanoparticles

The excessive use of antibiotics in clinical settings has resulted in the rapid expansion, evolution, and development of bacterial and microorganism resistance. It causes a significant challenge to the medical community. Therefore, it is important to develop new antibacterial materials that could replace traditional antibiotics. With the advancements in nanotechnology, it has become evident that metallic and metal oxide nanoparticles (MeO NPs) exhibit stronger antibacterial properties than their bulk and micron-sized counterparts. The antibacterial properties of silver nanoparticles (Ag NPs) and copper nanoparticles (Cu NPs) have been extensively studied, including the release of metal ions, oxidative stress responses, damages to cell integrity, and immunostimulatory effects. However, it is crucial to consider the potential cytotoxicity and genotoxicity of Ag NPs and Cu NPs. Numerous experimental studies have demonstrated that bimetallic nanoparticles (BNPs) composed of Ag NPs and Cu NPs exhibit strong antibacterial effects while maintaining low cytotoxicity. Bimetallic nanoparticles offer an effective means to mitigate the genotoxicity associated with individual nanoparticles while considerably enhancing their antibacterial efficacy. In this paper, we presented on various synthesis methods for Ag-Cu NPs, emphasizing their synergistic effects, processes of reactive oxygen species (ROS) generation, photocatalytic properties, antibacterial mechanisms, and the factors influencing their performance. These materials have the potential to enhance efficacy, reduce toxicity, and find broader applications in combating antibiotic resistance while promoting public health.

Photocatalytic C–H activation for C–C/CN/C–S bond formation over CdS: effect of morphological regulation and S vacancies

CdS catalytic materials were utilized to fabricate C–C, CN and C–S bonds for drug intermediates or other value-added products through the high bond energy, low polarity and strong inertia C–H bonds activation.