Niranjan Biswal

Facile synthesis of visible light responsive V2O5/N,S–TiO2 composite photocatalyst: enhanced hydrogen production and phenol degradation

A series of novel V2O5/N,S–TiO2 composite photocatalysts were fabricated by a solid state reaction route. The investigated composite materials were successfully characterised by XRD, DRUV-vis spectra, SEM, TEM, XPS, FTIR, NH3-TPD, BET-surface area and photoresponse studies. The photocatalytic applications of the composite materials were evaluated for hydrogen production under visible light irradiation (λ ≥ 400 nm) and phenol degradation under direct solar light. The V2O5 component played a key role for the visible light activity of the composite system at longer wavelengths. Among all the prepared materials, V2O5/N,S–TiO2 activated at 500 °C showed promising activity towards hydrogen production (296.6 μmol h−1) under visible light and successively degraded 88% of 100 mg L−1 phenol solution under direct solar light irradiation in just 4 h. The present investigation is of great importance in view of energy and environmental applications.

Facile fabrication of hierarchical N-doped GaZn mixed oxides for water splitting reactions

This report briefly highlights our recent research on a series of nanostructured N-doped GaZn mixed oxides concerning their fabrication, characterization and application for the generation of hydrogen from water. N-doped mixed oxides with hierarchical morphology are poised to be a most promising visible light sensitive semiconducting material for water splitting reactions.

Cs salt of tungstophosphoric acid-promoted zirconium titanium phosphate solid acid catalyst: An active catalyst for the synthesis of bisphenols

AbstractA series of novel xCsTPA–ZTP (x = 30, 40, 50, 60 and 80 wt%) solid acid composite catalysts were synthesized by ion-exchange process using cesium nitrate, tungstophosphoric acid (TPA), zirconium titanium phosphate (ZTP) with varied surface areas, acidities and microstructures. Detailed characterizations of the composite catalysts were done by Powder X-ray Diffraction (PXRD), Fourier Transform Infrared (FTIR) Spectroscopy, N2 adsorption desorption, Scanning Electron Microscopy (SEM-EDS) analysis, X-ray Photoelectron Spectroscopy (XPS) and Temperature Programmed Desorption (TPD). We have studied the catalytic activities, kinetics and reusability of the catalysts. 60CsTPA-ZTP is found to be an effective and re-usable catalyst for the synthesis of bisphenol A (BPA) and bisphenol F (BPF) using acetonitrile as solvent. ᅟ60CsTPA-ZTP is an efficient catalyst for the condensation of 8 mmol phenol and 1 mmol and 1 mmol acetone/formaldehyde at relatively low temperature (70 °C) in 7 h to give the highest conversion of 61.73% and 71.20% with selectivity of 85% and 88.35% towards Bisphenol A/Bisphenol F, respectively.