Copper-Nanoparticle-Decorated Hydrothermal Carbonaceous Carbon-Polydimethylsiloxane Nanocomposites: Unveiling Potential in Simultaneous Light-Driven Interfacial Water Evaporation and Power Generation.

This study introduces a hydrothermal synthesis method that uses glucose and Cu2+ ions to create a Cu-nanoparticle (NP)-decorated hydrothermal carbonaceous carbon hybrid material (Cu-HTCC). Glucose serves both as a reducing agent, efficiently transforming Cu2+ ions into elemental Cu nanostructures, and as a precursor for HTCC microstructures. An enhanced plasmon-induced electric field resulting from Cu NPs supported on microstructure matrices, coupled with a distinctive localized π-electronic configuration in the hybrid material, as confirmed by X-ray photoelectron spectroscopic analysis, lead to the heightened optical absorption in the visible-near-infrared range. Consequently, flexible nanocomposites of Cu-HTCC/PDMS and Cu-HTCC@PDMS (PDMS = polydimethylsiloxane) are designed as 2 and 3D structures, respectively, that exhibit broad-spectrum solar absorption. These composites promise efficient photo-assisted thermoelectric power generation and water evaporation, demonstrating commendable mechanical stability and flexibility. Notably, the Cu-HTCC@PDMS composite sponge simultaneously exhibits commendable efficiency in both water evaporation (1.47 kg m-2 h-1) and power generation (32.1 mV) under 1 sunlight illumination. These findings unveil new possibilities for innovative photothermal functional materials in diverse solar-driven applications.

Coral-like potassium and phosphorous doped graphitic carbon nitride structures with enhanced charge and mass transfer dynamics toward photocatalytic hydrogen peroxide production and microbial disinfection.

This study provided insight on the design of co-doped graphitic carbon nitride (g-C3N4) structures by using potassium dihydrogen phosphate (KH2PO4) as a promising material for the supply of potassium (K) and phosphorus (P) elements. The addition of KH2PO4 to the cyanuric acid-melamine complex (CM) solution stabilized its structure by coordinating potassium ions (K+) in the hexagonal pores and dihydrogen phosphate ions (H2PO4-) in dangling bonds on the edge sites. The resultant supramolecular structure (KP-CM) with a unique skeleton governed the polycondensation process, resulting in K and P co-doped g-C3N4 structures with a distinct coral-like morphology (KP-CN). Employing the KP-CM complex as a precursor could modify the optoelectronic behaviour of the photocatalysts via the synergistic effect of the co-doping process. It could also be beneficial in terms of economic considerations by increasing the catalyst synthesis yield. The resulting g-C3N4 showed a remarkable hydrogen peroxide (H2O2) production rate of 216 µmol L-1h-1 compared to the rate of the pristine sample of 137 µmol L-1h-1. It also exhibited significant photocatalytic antibacterial activity in Escherichia coli (E. coli) disinfection.

Synthesis of hexagonal rosettes of g-C3N4 with boosted charge transfer for the enhanced visible-light photocatalytic hydrogen evolution and hydrogen peroxide production.

Photocatalytic sustainable fuel production attracted extensive attention because of the urgent need of the society to shift from fossil fuels to solar fuels. Herein, the synthesis of hexagonal rosettes of g-C3N4 with an efficient performance toward hydrogen evolution and hydrogen peroxide production as the two kinds of solar fuels were reported. The hexagonal rosettes of g-C3N4 were simply fabricated via controlled solid-state polymerization of three-dimensional hexagonal rosettes of cyanuric acid-melamine adduct at 500 °C. The hexagonal rosettes of g-C3N4 showed an amorphous nature with an extremely high surface area of 400 m2 g-1. Also, the as-obtained catalyst demonstrated remarkable photocatalytic activity in hydrogen production of 1285 µmol g-1 h-1 and hydrogen peroxide production of 150 µmol g-1 h-1. The mechanism for the polymerization process of the cyanuric acid-melamine (CM) complex to hexagonal rosettes of g-C3N4 was thoroughly described employing electron microscopy tools. This study identified that the CM complex condensation is accomplished via a dehydration process by producing a highly condensed and active structure of g-C3N4, which is different from the previously reported condensation mechanism of the melamine and its derivatives performed through a deamination process.

Efficient Photodegradation of Rhodamine B and Tetracycline over Robust and Green g-C3N4 Nanostructures: Supramolecular Design.

Highly condensed g-C3N4 nanosheets with an exceptional surface area and porous structure were simply prepared by thermal condensation of stable preorganized supramolecular structures of cyanuric acid and melamine formed in water as the solvent. Different techniques were employed for the characterization of the structural, morphological, electrical, and optical features of the as-synthesized catalyst. All the characterizations confirmed the successful formation of nanosheets with magnificent properties compared to the pristine sample which was prepared by melamine polycondensation. Not only did these nanosheets exhibit a superb photocatalytic activity over the degradation of tetracycline (over 60%) and rhodamine B (100%) under visible light irradiation just for 15 min, but they also could maintain their stability during the reaction keeping over 98% of their original degradation even in 5 cycles. Superoxide anion radicals and holes were determined to be the main active species by trapping experiments. LC-Mass analysis was also performed to identify the intermediates and propose the possible pathway for photodegradation of tetracycline. The promising performance of this catalyst can be a notable step forward for prosperous industrial applications in the field of photodegradation of hazardous and not-easily degradable organic compounds in wastewater treatment plants.