Search

Visible-light-driven photo-fenton-like catalytic activity and photoelectrochemical (PEC) performance of nitrogen-doped brownmillerite KBiFe2O5 (KBFO) are investigated. The effective optical bandgap of KBFO reduces from 1.67 to 1.60 eV post N-doping, enabling both enhancement of visible light absorption and photoactivity. The photo-fenton activity of KBFO and N-doped KBFO samples were analysed by degrading effluents like Methylene Blue (MB), Bisphenol-A (BPA) and antibiotics such as Norfloxacin (NOX) and Doxycycline (DOX). 20 mmol of Nitrogen-doped KBFO (20N-KBFO) exhibits enhanced catalytic activity while degrading MB. 20N-KBFO sample is further tested for degradation of Bisphenol-A and antibiotics in the presence of H2O2 and chelating agent L-cysteine. Under optimum conditions, MB, BPA, and NOX, and DOX are degraded by 99.5% (0.042 min-1), 83% (0.016 min-1), 72% (0.011 min-1) and 95% (0.026 min-1) of its initial concentration respectively. Photocurrent density of 20N-KBFO improves to 8.83 mA/cm2 from 4.31 mA/cm2 for pure KBFO. Photocatalytic and photoelectrochemical (PEC) properties of N-doped KBFO make it a promising candidate for energy and environmental applications. [ABSTRACT FROM AUTHOR]

One-dimensional AlN microrods have been grown on sapphire substrate by oxide-assisted vapor utilizing chemical vapor deposition method via vapor-solid mechanism. The structure and morphology of as-grown samples were analyzed by HRXRD, Raman, FT-IR, SEM and TEM. AlN microrods possess single crystalline hexagonal structure with average diameter ~0.7 µm and length ~5 µm. Chemical compositions have been estimated from EDX analysis. X-ray photoelectron peaks of Al, N, O and C were observed on the surface of AlN microstructures. Photoluminescence spectrum reveals broad ultraviolet, blue emission bands corresponding to deep-level defects. From the optical absorption spectrum direct bandgap was found to be 5.66 eV. [ABSTRACT FROM AUTHOR]

One of the major aspects and advantages of solar energy conversion is the photocatalytic hydrogen generation using semiconductor materials for an eco-friendly technology. Designing a low-cost efficient material to overcome limited light absorption as well as rapid recombination of photogenerated charge carriers is essential to achieve considerable hydrogen generation. In recent years, sulfide based semiconductors have attracted scientific research interest due to their excellent solar response and narrow band gap. The present review focuses on the recent approaches in the development of hierarchical ternary sulfide based photocatalysts with a special focus on ZnIn2S4. We also observe how the electronic structure of ZnIn2S4 is beneficial for water splitting and the various strategies involved for improving the material efficiency for photocatalytic hydrogen generation. The review places emphasis on the latest advancement/new insights on ZnIn2S4 being used as an efficient material for hydrogen generation through photocatalytic water splitting. Recent progress on essential aspects which govern light absorption, charge separation and transport are also discussed in detail. [ABSTRACT FROM AUTHOR]

• An effective photoactive Z-Scheme heterostructure based on Zinc Indium Sulfide/Calcium Ferrite composite. • Effective degradation of persistent antibiotics with different structures. • Easy retrieval of the photocatalyst post degradation using dialysis bags. • Utilization of LED as a cost-efficient light source for photodegradation of organic pollutants. This work leverages the synergetic effect of chalcogenide ZnIn 2 S 4 (Zinc Indium Sulfide) and brownmillerite Ca 2 Fe 2 O 5 (Calcium Ferrite) composite (ZC). The ZC composite with surface oxygen vacancy, superior light absorption, charge separation, good stability, and recyclability was prepared. The material could effectively degrade various antibiotics (having different structures), such as Metronidazole, Nitrofurantoin, Sulfamethoxazole, and Tetracycline with 98 %, 99.5 %, 98.4 %, and 82.4 % efficiency respectively. A customized LED chamber was used as a cost-efficient photoreactor. Post-degradation, dialysis bags were used effectively to retrieve the photocatalytic material from water, as corroborated by leaching studies based on the Inductively coupled plasma-optical emission spectrometry (ICP-OES). This work marks a significant leap forward in the quest for wastewater treatment, offering a versatile solution. [Display omitted] [ABSTRACT FROM AUTHOR]

Visible-light-driven photo-fenton-like catalytic activity and photoelectrochemical (PEC) performance of nitrogen-doped brownmillerite KBiFe2O5 (KBFO) are investigated. The effective optical bandgap of KBFO reduces from 1.67 to 1.60 eV post N-doping, enabling both enhancement of visible light absorption and photoactivity. The photo-fenton activity of KBFO and N-doped KBFO samples were analysed by degrading effluents like Methylene Blue (MB), Bisphenol-A (BPA) and antibiotics such as Norfloxacin (NOX) and Doxycycline (DOX). 20 mmol of Nitrogen-doped KBFO (20N-KBFO) exhibits enhanced catalytic activity while degrading MB. 20N-KBFO sample is further tested for degradation of Bisphenol-A and antibiotics in the presence of H2O2 and chelating agent L-cysteine. Under optimum conditions, MB, BPA, and NOX, and DOX are degraded by 99.5% (0.042 min-1), 83% (0.016 min-1), 72% (0.011 min-1) and 95% (0.026 min-1) of its initial concentration respectively. Photocurrent density of 20N-KBFO improves to 8.83 mA/cm2 from 4.31 mA/cm2 for pure KBFO. Photocatalytic and photoelectrochemical (PEC) properties of N-doped KBFO make it a promising candidate for energy and environmental applications. [ABSTRACT FROM AUTHOR]

Photocatalysis requires light absorption as well as efficient extraction of the photogenerated electron–hole pairs to chemically active sites. To avoid electron–hole recombination, we need tailored nanostructures which can demonstrate novel light absorption and thermodynamic properties. This work shows that band gap modification/narrowing due to the formation of solid solution along with an increased surface area of the nanostructures are ideal for solar harvesting and is a self sufficient photocatalytic agent even in absence of a co-catalyst. The present study suggests that the rate of H 2 production for GaN was negligible and it increased to 32.43 μmol/g/h for the solid solution under visible light irradiation (>400 nm) even in the absence of a co-catalyst. The apparent quantum yield (AQY) efficiency of H 2 evolution was found to be 0.8%. This highly desirable increased H 2 generation activity is attributed to the additional linewidth broadening in the photoluminescence spectra of nanostructured wurtzite Ga 1−x Zn x O 1−z N z solid-solution due to Ga/Zn and N/O interdiffusion giving rise to a modified bandgap and N2p-O2p interaction in the lattice. These inferences are also corroborated by diffuse reflectance spectra of the samples. For the first time, origin of hitherto unreported weak features appearing in the low energy Raman spectrum is also discussed. A series of characterization tools including structural, microstructural, optical, spectroscopic and Photocatalytic hydrogen production studies were employed to support our claim. [ABSTRACT FROM AUTHOR]