Multifarious function layers photoanode based on g-C 3 N 4 for photoelectrochemical water splitting

Synergistic Enhancement of Water-Splitting Performance Using MOF-Derived Ceria-Modified g-C3N4 Nanocomposites: Synthesis, Performance Evaluation, and Stability Prediction with Machine Learning

Diminishing the charge recombination rate by improving the photoelectrochemical (PEC) performance of graphitic carbon nitride (g-C3N4) is essential for better water oxidation. In this concern, this research explores the competent approach to enhance the PEC performance of g-C3N4 nanosheets (NSs), creating their nanocomposites (NCs) with metal-organic framework (MOF)-derived porous CeO2 nanobars (NBs) along with ZnO nanorods (NRs) and TiO2 nanoparticles (NPs). The synthesis involved preparing CeO2 NBs and g-C3N4 NSs through the calcination of respective precursors, while the sol-gel method is employed for ZnO NRs and TiO2 NPs. Following the subsequent analysis of the physicochemical properties of the materials, the binder-free brush-coating method is deployed to fabricate NC-based photoanodes, followed by an evaluation of the PEC performance through various electrochemical techniques. Remarkably, the binary g-C3N4/CeO2 NCs with 20 wt % CeO2 NBs (gC20 NCs) exhibited a significantly enhanced current density of 0.460 mA/cm2 at 1.23 V vs reversible hydrogen electrode, which is 2.3 times greater than that of bare g-C3N4 NSs (0.195 mA/cm2). Further improvements are observed with ternary gC20/TiO2 (gCT50) and gC20/ZnO (gCZ50) NCs, achieving current densities of 1.810 and 1.440 mA/cm2, respectively. These enhanced current densities are attributed to increased donor densities, reduced charge transfer resistances, and efficient charge transport within the NCs. In addition, higher surface areas with beneficial instinctive defects are perceived for gCT50 and gCZ50 NCs, as revealed by Brunauer-Emmett-Teller and electron spin resonance analysis. Finally, the stability of gCZ50 and gCT50 NC-based photoanodes is predicted and forecasted with the help of the recurrent neural network-based long short-term memory technique. Overall, this study demonstrates the efficacy of organic-inorganic hybrids for efficient photoanodes, facilitating advancements in water-splitting studies.

Novel smart fiber/metal/chitosan composite as a filter for self-detoxifying photocatalytic wastewater remediation and biomedical applications

Wastewater treatment remains the most significant delinquent issue world-wide. Generally, wastewater treatment involves filtration followed by acidified de-emulsification through photocatalytic reduction. The aim of the present study is to reduce the use of nanoparticles in wastewater treatment and also to find an appropriate alternative to replace cotton fiber filters used in water treatment plant. The cotton fiber filters are highly prone to bacterial film development leading to bactericidal degradation of the fibers. We developed a ZnO-chitosan nanocomposite coated fiber for wastewater treatment to enhance its photocatalytic activity under acidic condition. The fiber showed high degree of photocatalytic degradation activity, reducing rhodamine B dye, chemical oxygen demand and chromium levels in the synthetic wastewater to 37, 79 and 51% respectively under highly acidic condition. Additionally, ZnO-chitosan nanocomposite did not cause mortality on Danio rerio embryo after 72 h incubation. The ZnO-chitosan nanocomposite coated fiber showed strong antibacterial activity against Escherichia coli and Staphylococcus aureus with a reduction of 96% and 99% respectively. This study demonstrated the potential of a novel smart fiber in wastewater treatment and biomedical applications.

Fabrication and Characterization of the Broccoli-like Structured CuO Thin Films Synthesized by a Facile Hydrothermal Method and Its Photoelectrochemical Water Splitting Application

CuO thin films with broccoli-like structure were prepared using a facile hydrothermal method to construct photocathodes for water-splitting application. The morphological, structural, and optical properties of thin films were characterized and measured using several techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and ultraviolet-visible spectroscopy (UV-Vis). The thickness, structure, and morphology of CuO thin films can be controlled by varying the precursor concentration (Cp) and reaction temperature (Tr), which are also discussed. Moreover, the electrical properties of CuO thin films were also measured in the three-electrode system. The photocurrent density of photocathodes, when synthesized by a 0.5 M solution at 150 °C for 12 h, was 0.5 mA/cm2 at −0.6 V vs. Ag/AgCl, which is 1.8 times higher than that of photocathodes synthesized in a 0.1 M solution at 100 °C with the same reaction time. In addition, increasing the reaction temperature and precursor concentration aided in the enhancement of the IPCE and APCE values, which peaked at a wavelength range of 330–400 nm.

Nanostructured CuO with a thin g-C3N4 layer as a highly efficient photocathode for solar water splitting

A g-C₃N₄/CuO nanostructure featuring improved photoelectrochemical properties was successfully prepared using a facile and cost-effective method involving electrodeposition and thermal oxidation.

Synthesis of hollow donut-like carbon nitride for the visible light-driven highly efficient photocatalytic production of hydrogen and degradation of pollutants

Design and synthesis of highly effective, hollow, erythrocyte-like g-C₃N₄ photocatalysts towards the degradation of environmental pollutants.