ABSTRACT
A Cu-doped Fe2O3/g-C3N4 composite, synthesized via a straightforward hydrothermal process with controlled morphologies, represents a significant advancement in supercapacitor electrode materials. This study systematically analyzes the impact of Cu doping in Fe2O3 and its synergistic combination with g-C3N4 to understand their influence on the electrochemical performance of the resulting composite, focusing on Cu doping in Fe2O3 rather than varying Fe2O3/g-C3N4 content. The comprehensive characterization of these composites involved a suite of physicochemical techniques. X-ray diffraction (XRD) confirmed the successful synthesis of the composite, while field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were employed to investigate the morphological attributes of the synthesized materials. X-ray photoelectron spectroscopy (XPS) spectra confirmed the elemental composition of the composite with 6% Cu doped Fe2O3/g-C3N4. The composite electrode, which incorporated 6% Cu doped Fe2O3 with g-C3N4, exhibited exceptional cycling stability, retaining 94.22% of its capacity even after 2000 charge-discharge cycles at a current density of 5 mA cm-2. Furthermore, this Cu doped Fe2O3/g-C3N4 composite electrode demonstrated impressive electrochemical performance, boasting a specific capacitance of 244.0 F g-1 and an impressive maximum energy density of 5.31 W h kg-1 at a scan rate of 5 mV s-1. These findings highlight the substantial potential of the Cu doped Fe2O3/g-C3N4 electrode for supercapacitor applications.
ABSTRACT
Unique N doped Sn3O4 nanosheets have been demonstrated successfully using a facile hydrothermal method. Investigations of the triclinic phase and the impurities were performed using powder X-ray diffraction analysis (XRD) and Raman spectroscopy. The morphological analysis demonstrated a rectangular intra- and inter-connected nanosheet-like structure. The length of the nanosheets was observed to be in the range of 200-300 nm and the thickness of the nanosheets was less than 10 nm. The optical study reveals an extended absorption edge into the visible region, owing to the incorporation of nitrogen into the lattice of Sn3O4, which was further confirmed using X-ray photoelectron spectroscopy (XPS). Considering the band structure in the visible region, the photocatalytic activities of pristine and N doped Sn3O4 nanosheets for hydrogen evolution from water under natural sunlight were investigated. 4% N-Sn3O4 showed a higher photocatalytic activity (654.33 µmol-1 h-1 0.1 g-1) for hydrogen production that was eight times that of pristine Sn3O4. The enhanced photocatalytic activity is attributed to the inhibition of charge carrier separation owing to the N doping, morphology and crystallinity of the N-Sn3O4 nanostructures. A stable efficiency was observed for three cycles, which clearly shows the stability of N-Sn3O4.
ABSTRACT
Nanomaterials have recently gained significant interest as they are believed to offer an outstanding prospect for use in environmental remediation. Among many possible candidates, due to their useful properties including magnetic nature, wide surface area, and high absorptivity, ferrite materials hold tremendous appeal, allowing them to be used for multifaceted applications. In the present study, using a sol-gel auto combustion process, a magnetically separable Zn1-x Co0.5x Mg0.5x Fe2O4 (x = 0.0, 0.25, 0.50, 0.75, 1.0) ferrite with superior photocatalytic activity for dye degradation was manufactured. Rietveld refinement and FTIR studies confirm that a single-phase cubic spinel system was built for all samples with crystallite sizes of 34-57 nm. VSM has determined the magnetic properties of the samples at room temperature. With the introduction of Mg2+ and Co2+ in the Zn ferrites, a transformation from the soft superparamagnetic activity to the hard ferromagnetic character was reported. Considering the band structure in the visible region, the photocatalytic activities of the Zn1-x Co0.5x Mg0.5x Fe2O4 ferrites for the degradation of the MB dye under natural sunlight were investigated. Zn0.25Co0.375Mg0.375Fe2O4 showed an efficiency of degradation of 99.23% for MB dye with a quick 40 min irradiation period with high reusability of up to four cycles.
ABSTRACT
Herein, a facile hydrothermally-assisted sonochemical approach for the synthesis of a ZnO decorated Sn3O4 nano-heterostructure is reported. The phase purity of the nano-heterostructure was confirmed by X-ray diffraction and Raman spectroscopy. The morphological analysis demonstrated a nanosheet-like structure of Sn3O4 with a thickness of 20 nm, decorated with ZnO. The optical band gap was found to be 2.60 eV for the ZnO@Sn3O4 nano-heterostructure. Photoluminescence studies revealed the suppression of electron-hole recombination in the ZnO@Sn3O4 nano-heterostructure. The potential efficiency of ZnO@Sn3O4 was further evaluated towards photocatalytic hydrogen production via H2O splitting and degradation of methylene blue (MB) dye. Interestingly, it showed significantly superior photocatalytic activity compared to ZnO and Sn3O4. The complete degradation of MB dye solution was achieved within 40 min. The nano-heterostructure also exhibited enhanced photocatalytic activity towards hydrogen evolution (98.2 µmol h-1/0.1 g) via water splitting under natural sunlight. The superior photocatalytic activity of ZnO@Sn3O4 was attributed to vacancy defects created due to its nano-heterostructure.
