Architecting the Z-scheme heterojunction of Gd2O3/g-C3N4 nanocomposites for enhanced visible-light-induced photoactivity towards organic pollutants degradation.

A basic calcination process in one step was employed to create g-C3N4 photocatalytic composites modified by Gd2O3 nanoparticles. SEM (scanning electron microscopy), FTIR (Fourier-transform infrared spectroscopy), XRD (X-ray diffraction), EIS (electrochemical impedance spectroscopy), PL (photoluminescence studies) as well as TEM (transmission electron microscopy), XPS (X-ray photoelectron spectroscopy), and CV (cyclic voltammetry) were employed to explain the structural traits, optical properties, and morphological features of the processed photocatalyst. The findings show that Gd2O3 (Gd) does not affect the sample's crystalline structure but rather increases g-C3N4 surface area by spreading it superficially. Furthermore, Gd can redshift the light absorption peak, reduce the energy gap, and improve the efficiency with which photogenerated holes and electrons are removed in g-C3N4. The surface morphology of g-C3N4, in particular, could be significantly enhanced. We similarly employed three distinct photocatalytic complexes of Gd2O3 and g-C3N4 in 1:1, 2:1, and 3:1 proportions to degrade methylene blue (MB). After 100 min in visible light (400-800 nm), the photodegradation rate of composites is 58.8% for 1:1 (GG1), 94.5% for 2:1 (GG2), and 92% for 3:1 (GG3). In addition to the MB dye, the photocatalytic activity of synthesized materials was also studied for methyl orange. The result shows phenomenal degradation values, i.e.; for GG1 86%, GG2 96%, and for GG3 84.6%. The narrow band gap that separates the photogenerated electron and hole enhances g-C3N4 ability to degrade photo-catalytically. From the result, we concluded that the photocurrent and cyclic photocatalytic degradation of methylene blue shows that a composition of 2:1 Gd2O3/g-C3N4 has high photocatalytic stability.

Mg/Li@GCN as highly active visible light responding 2D photocatalyst for wastewater remediation application.

In this study, a highly visible light responding 2D photocatalytic material has been prepared and analysed for its potential for photodegradation of organic pollutants. The pristine GCN has been co-doped with Mg/Li using the facile synthesis route. The prepared photocatalytic materials were then analysed using characterisation techniques like X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, diffuse reflectance spectra (DRS) and photoluminescence spectroscopy (PL) analysis. The prepared samples were analysed for photocatalytic degradation analysis towards methylene blue dye. The apparent rate constant value increased up to 5.4 times in the case of the GCNML (0.5,2) sample in comparison to GCNP. In addition, the GCNML (0.5,2) sample was also analysed for degradation of crystal violet (CV) (97% in 80 min), rose bengal (RB) (84% in 120 min) and methyl orange (MO) (45% in 120 min) dyes. The result obtained from the study confirmed that GCNML (0.5,2) can act as a potential photocatalyst for wastewater remediation application.

Gd(III) metal-organic framework as an effective humidity sensor and its hydrogen adsorption properties.

Metal-organic frameworks (MOFs) represent a class of nanoporous materials built up by metal ions and organic linkers with several interesting potential applications. The present study described the synthesis and characterization of Gd(III)-based MOF with the chemical composition [Gd(BTC)(H2O)]·DMF (BTC - trimesate, DMF = N,N'-dimethylformamide), known as MOF-76(Gd) for hydrogen adsorption/desorption capacity and humidity sensing applications. The structure and morphology of as-synthesized material were studied using powder X-ray diffraction, scanning and transmission electron microscopy. The crystal structure of MOF-76(Gd) consists of gadolinium (III) and benzene-1,3,5-tricarboxylate ions, one coordinated aqua ligand and one crystallization DMF molecule. The polymeric framework of MOF-76(Gd) contains 1D sinusoidally shaped channels with sizes of 6.7 × 6.7 Å propagating along c crystallographic axis. The thermogravimetric analysis, heating infrared spectroscopy and in-situ heating powder X-ray diffraction experiments of the prepared framework exhibited thermal stability up to 550 °C. Nitrogen adsorption/desorption measurement at -196 °C showed a BET surface area of 605 m2 g-1 and pore volume of 0.24 cm3 g-1. The maximal hydrogen storage capacity of MOF-76(Gd) was 1.66 wt % and 1.34 wt % -196 °C and -186 °C and pressure up to 1 bar, respectively. Finally, the humidity sensing measurements (water adsorption experiments) were performed, and the results indicate that MOF-76(Gd) is a suitable material for moisture sensing application with a fast response (11 s) and recovery time (2 s) in the relative humidity range of 11-98%.