Ceramic Supported Catalytic Membrane Based Fermentative Reactor Process for Biohydrogen Production from Industrial Wastewater

Biohydrogen production from carbohydrate rich organic wastes by fermentation route emerges as a sustainable option for renewable energy generation. Application of membrane technology in fermentation process can be beneficial as the membrane facilitate in removing the H2 generation inhibitors from the fermentation reaction, such as volatile fatty acids (VFA) and alcohols and improves the process yield. In the present study a novel nickel oxide (NiO) based ceramic catalytic membrane is developed on clay-alumina tubular support withan intermediate bentonite clay coating for application in membrane bioreactor (MBR) process. The prepared membrane showed highly hydrophilic surface involving static water contact angle of 320. A reduction in the clean water permeability (CWP) ofmembrane was observed due to the surface coating, 25 Lm-2h-1bar-1in comparison with that of the pristine support,105 Lm-2h-1bar-1.From FESEM and EDX analysis, impregnation of NiO,~28-29 (wt%) was evident on the membrane surface.Further, VFA rejection efficiency of the catalytic membrane was observed high with respect to butyric acid (50%) and acetic acid (60%) compared to thepristine support (30–40%). The membranes were used ina batch mode cylindrical bioreactor (7 L)made with stainless steelfor the dark fermentation processutilizing simulated molasses wastewater having initial COD of 8000 mg/L to produce biohydrogen under anaerobic condition in the presence of Clostridium sp. with controlled pH (6-7), temperature 35-400C and stirring conditions (300 rpm).The performance efficiency of fermentation process was compared in three types of system: i) without membrane; ii) with pristine supports and iii) with catalytic membranes.After 120 h of fermentation, biohydrogen generation was recorded as 0.15, 0.35 and 0.48 mol H2/mol of carbohydrate in the systems (i), (ii) and (iii) respectively. Withappropriate optimizationof the wastewater composition in terms of carbohydrate content, use of microorganism consortium such as Clostridium. sp. and Enterobactor. sp. and employing a novel bi-metallic (Ni-Fe) based catalytic membrane can enhance the biohydrogen yield towards establishing a sustainable waste-to-energy production pathway

Ceramic Membrane Based Bioreactor Process for Biohydrogen Production from Molasses Wastewater

The gradual scarcity of fossil fuel resources and associated environmental restrictions opens the research avenues worldwide to explore on clean energy sources like hydrogen as a renewable and sustainable energy source with a high energy content and no negative environmental effects. Various organic wastes with high carbohydrate content are mostly used to produce biohydrogen by fermentation process in presence of suitable bacteria. In this regard, integrating a ceramic membrane into a fermentative reactor may be a desirable way to increase the production of biohydrogen. The present study is aimed to construct a novel ceramic membrane bioreactor where molasses wastes are fermented in presence of anaerobic bacteria Clostridium sp. to produce biohydrogen through dark fermentation process. The bioreactor study was done in a SS bioreactor (7 L) in batch mode with simulated molasses wastewater with controlled pH, temperature and stirring condition. Metal oxide based ceramic membrane was prepared on clay-alumina support and characterised by FESEM, EDX, FTIR etc. The performance was further measured in terms of clean water permeability (CWP), % recovery of volatile fatty acid,% production of hydrogen and chemical oxygen demand (COD) reduction. The gas samples and VFA were analysed using GC and HPLC, respectively. Biohydrogen production started after 48 h of fermentation in membrane bioreactor, reaching its maximum yield of 0.48 mol H2/mol of carbohydrate after 120 h and wastewater COD was reduced by ~ 40 %.Optimization of wastewater composition, external physicochemical and microbial environment along with the ceramic membrane characteristics can be crucial in enhancement of bioH2 yield towards establishing a sustainable pathway for waste to energy production

Discovery of Magnetic Field Line Dependent Anisotropic Chemiresistive Response in Magnetite: A New Piece to the Puzzle Of Magnetoreception

Chemiresistive materials, which alter their electrical resistance in response to interactions with surrounding chemicals, are valued for their robustness, rapid detection ability and high sensitivity. Recent research has revealed that the sensing performance of these materials can be enhanced by applying an external magnetic field. In this study, we report a novel finding in the chemiresistive behaviour of magnetite (Fe3O4), where its response has been found to be modulated in an anisotropic manner when exposed to an external magnetic field, analogous to Earth's magnetic field. Remarkably, substantial variations have been observed in response to analytes naturally present in the atmosphere. A remarkable increase in response was observed upon applying a 0.05 mT magnetic field, resulting in a more than 26-fold enhancement in sensitivity to relative humidity (98%), as well as a greater than 10-fold improvement in response to CO2 and a 25-fold increase in response to NO2. This chemiresistive response exhibits a strong anisotropic dependence on the strength, direction and inclination of the magnetic field, suggesting that magnetite's electrical resistance dynamically adapts to both magnetic and chemical environmental changes. The observed behaviour under an Earth-like magnetic field closely mirrors the magnetoreception seen in biological species that rely on magnetite for navigation. This finding may provide new insights into the mechanisms behind magnetite-based magnetoreception observed in various biological species

Phosphor in Glass (PiG) and Glass-ceramic Composite: Future Prospects for High-Performance WLEDs

The demand for energy-efficient, thermally stable, and spectrally tunable white light-emitting diodes (WLEDs) has led to intensive research into advanced phosphor materials. Commercially, W-LEDs are fabricated by combining GaN-based blue chip with luminescent layer comprising YAG: Ce3+ yellow phosphor in resin (PiR). However, due to their chromatic aberration and poor white light performance, the widened applications of W-LEDs in medical lighting is limited. At present, various fluorescent systems and photoluminescence-tunable strategies are actively being investigated using a variety of techniques. Phosphor-in-glass (PiG) and rare-earth ion (REI) doped glass andglass-ceramic composites have emerged as promising candidates for nextgeneration white light-emitting diodes (W-LEDs), owing to their superior thermal stability, optical performance, and structural reliability compared to conventional phosphor-in-resin (PiR) systems1 . In this study, two complementary approaches are explored to enhance the performance of W-LEDs. At first, Ce³⁺ :Y3Al5O12 (YAG)-based PiG composites were fabricated using ZnO– Na2O–Bi2O3–B2O3–SiO2 borosilicate glass matrix which has low softening point and closely matching refractive index with the index of phosphor. Notably, the fabricated PiG composites exhibited excellent thermal stability, retaining 90% of their luminescence intensity at 175°C, while the conventional phosphor-in-resin (PiR) systems could retain only 70%. Parallelly, Dy3+ - doped BaO–MgO–La2O3–Al2O3–SiO2 glass has been synthesized and converted them to glassceramics composite to havebetter thermal stability, low phonon energy, and good crystal environment for REI. The formation of BaAl2Si2O8 crystalline phases provided a favorable crystalline environment for Dy³⁺ ions, resulting in enhanced white light emission due to yellow at 580 nm (4 F9/2 →  6H13/2) along with blue emissions at 479 nm (4 F9/2 →  6H15/2) under excitation at 351 nm. Photoluminescence intensity was found to be 3–6 times higher in glass-ceramics compared to the precursor glass, accompanied by improved thermal and structural stability. Colorimetric analysis showed emission coordinates leaning toward the warm white region (X= 0.3606, Y=0.3814) indicating suitability for human-centric lighting applications. These two material strategies demonstrate the practical synergy between PiG and REI-doped glass-ceramics in addressing key limitations of commercial W-LEDs, such as poor thermal tolerance and limited color tunability. Their high efficiency, color tunability and durability make them strong candidates for solid-state lighting applications, including those requiring precise CCT control and long-term reliability

A Sustainable Approach for Bio-Hydrogen Production from Molasses Waste with Ceramic Membrane Bioreactor

Modern day life is much dependent on fossil fuel which has various environment constraints and its resource is also limited. Hydrogen is an important renewable and sustainable energy source with high energy value and no adverse effect on environment. Different carbohydrate rich waste materials have been used for bio-hydrogen production by dark fermentation process using anaerobic bacteria. In this context, integration of ceramic catalytic membrane in membrane bioreactor can be an attractive option to enhance the production of bio-hydrogen. The present study is focused on design of an innovative fermentative bioreactor process for bio-hydrogen production by dark fermentation process utilizing molasses waste and anaerobic bacteria Clostridium sp. (MTCC 11078). Dark fermentation experiment for bio-hydrogen production was carried out in 7 L bioreactor in batch mode initially with synthetic molasses having initial pH 7 and glucose conc. 5g/L at 450C with continuous stirring at 300 rpm for 7 days. Initial result showed that after 48 h of fermentation process bio-hydrogen production was started and highest production (0.2 mol H2/mol of carbohydrate) was achieved after 120 h and COD of synthetic molasses was decreased by 25%. The ceramic based catalytic membranes indigenously prepared on clay-alumina support would be used in future for treatment of molasses wastewater with catalytic activity to increase the rate of bio-hydrogen production. Overall, the present study proposes a novel ceramic catalytic membrane based bioreactor process that integrates wastewater treatment and catalysis functions to enhance bio-hydrogen production from industrial waste. This innovation has the potential to address the existing challenges in bio-hydrogen production and significant improvement in the efficiency, providing a sustainable and efficient solution for renewable energy applications

Immobilized Gold Nanoparticles on a Glass-Based Scaffold for Direct Solar-Driven H2 from Water Vapor

Solar-driven green hydrogen (H2) production through photocatalytic water splitting is a promising solution to combat climate change. A key challenge lies in developing photocatalyst materials capable of efficiently splitting water vapor under practical conditions. In this study, we present a photocatalytic system based on gold nanoparticles immobilized on a glass-based porous scaffold through reactive metal support interactions. This structure exhibits a high solar-to-hydrogen (STH) conversion efficiency of 2.2% under simulated solar light. Long-term cycling tests demonstrate stable H2 evolution, with observed declines in efficiency caused by surface hydroxyl and carboxyl group formation, although it is effectively restored through plasma treatment. These findings provide valuable insights into the design of robust and efficient photocatalytic materials, advancing the potential path for scalable commercial applications

Bi−S Bond Mediated Direct Z-Scheme BiOCl/Cu2SnS3 Heterostructure for Efficient Photocatalytic Hydrogen Generation

The advancement of photocatalytic technology for solar-driven hydrogen (H2) production remains hindered by several challenges in developing efficient photocatalysts. A key issue is the rapid recombination of charge carriers, which significantly limits the light-harvesting ability of materials like BiOCl and Cu2SnS3 quantum dots (CTS QDs), despite the faster charge mobility and quantum confinement effect, respectively. Herein, a BiOCl/CTS (BCTS) heterostructure was synthesized by loading CTS QDs onto BiOCl 2D nanosheets (NSs), that demonstrated excellent photocatalytic activity under visible light irradiation. The improved hydrogen generation rate (HGR) was primarily due to an interfacial Bi−S bond formation, which facilitates the creation of direct Z-scheme heterojunction and an internal electric field at the interface, promoting efficient charge transfer between BiOCl and CTS. Moreover, due to the amalgamation of Bi−S bond formation and interfacial electric field, the optimized BCTS-5% heterostructure exhibited a high HGR of 8.27 mmol g−1 h−1, and an apparent quantum yield (AQY) of 61 %, ~4 times higher than pristine BiOCl. First-principle density functional theory (DFT) calculations further revealed the presence of a Bi−S bond with a bond length of ~2.85 Å and a minimal work function of 2.37 eV for the heterostructure, both of which are critical for enhancing H2 generation efficiency

Self-Powered device enabled by a Chemically Etched MXene/P(VDF-TrFE) composite for ambient Energy Harvesting

In the energy domain, Piezoelectric Energy Harvesters offer a sustainable solution for converting ambient mechanical energy into usable electrical power for self-powered devices. In our work, we present a flexible and efficient piezoelectric energy harvester (PEH) based on a composite film of poly (vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] and MXene (Ti₃C₂Tₓ) nanosheets. MXene (Ti₃C₂Tₓ) nanosheets were synthesized via a chemical etching method and uniformly dispersed within the P(VDF-TrFE) matrix to fabricate composite films via a solution casting and annealing method. These were incorporated into P(VDF-TrFE) matrix to enhance the piezoelectric and dielectric properties of the composite. Different weight percentages of MXene were incorporated to analyse the effect on electroactive property. The incorporation of MXene facilitates improved β-phase crystallinity and interfacial polarization, leading to enhanced energy harvesting performance. The optimized composite film exhibited a maximum output AC voltage of 26 V and peak power of 50 µW under periodic mechanical stress and also have some sensing response upon different types of mechanical stresses. This study highlights the synergistic role of MXene in enhancing the electromechanical conversion efficiency of P(VDF-TrFE) and offers a promising strategy for the development of next-generation self-powered wearable electronics, flexible sensors

Polyoxometalate-Loaded Reduced Graphene Oxide-Modified Metal Vanadate Catalysts for Photoredox Reactions Through an Indirect Z-Scheme Mechanism

The growing energy demand and environmental concerns have accelerated research on the emergence of photocatalysts for solar fuel generation and environmental remediation. Metal vanadates, such as silver vanadate (AV) and copper vanadate (CV), are considered promising visible-light active photocatalysts owing to their narrow bandgap and suitable band structure; however, they are limited by rapid electron–hole recombination. To overcome this limitation, amalgamation with polyoxometalate (POM)-loaded reduced graphene oxide (RGO)-based novel co-catalysts is a facile strategy to improve photocatalytic performance. Herein, metal vanadates were deposited on polyoxometalate-loaded reduced graphene oxide (RPOM) via a one-pot coprecipitation method. The developed RPOM–AV and RPOM–CV composites exhibited photocurrent densities of 223.7 and 85.8 μA cm−2, which were 51 times and 6 times higher than those of pristine AV and CV, respectively, owing to the remarkable augmentation in the donor density after formation of composites. Moreover, the RPOM–AV composites exhibited photocatalytic Cr(VI) reduction of up to 94% in 60 minutes with a high rate constant of 0.044 min−1 and 94% removal of the rose bengal dye in 120 minutes through adsorption. The RPOM–CV composites demonstrated 96% photocatalytic degradation of methylene blue dye at a rate constant of 0.011 min−1. The excellent photocatalytic activity of RPOM–metal vanadate composites was attributed to the formation of an indirect Z-scheme heterojunction between metal vanadates and POM, in which RGO acted as a suitable electron-mediator, facilitated the charge transfer, boosted the separation of photogenerated charge carriers, and lowered the electron–hole recombination. The present work provides an innovative approach toward the development of polyoxometalate-based composites for wastewater remediation

Direct Z-Scheme BiOCl/α-Fe2O3Heterojunction: A Pathway to Enhanced Photoelectrochemical Water Splitting

Inadequate solar absorption and inefficient charge separation are the primary factors that limit the conversion efficiency in photoelectrochemical water-splitting systems.In this work, a BiOCl/α-Fe2O3(BFE) heterostructure was synthesized using a direct deposition technique, varying the loading of α-Fe2O3nanoparticles on BiOCl nanosheets to optimize its photoelectrochemical (PEC) properties.The well-dispersed α-Fe2O3nanoparticles on the BiOCl surface enhance light absorption in the visible region while accelerating charge separation efficiency.The optimized BFE2 heterostructure exhibits a photocurrent density that is 2.5 times higher than pure BiOCl and 87 times greater than α-Fe2O3, demonstrating its superior photoelectrochemical performance.The charge carrier lifetime under continuous light irradiation reveals that BFE2 exhibits a higher value of approximately 3.97 seconds, indicating an enhanced availability of free charge carriers in the optimized BFE2 heterostructure.A direct Z-scheme heterojunction is proposed to form at the BiOCl/α-Fe2O3interface, effectively facilitating charge separation and enhancing charge mobility.This work offers valuable insights into developing a simple and cost-effective approach for synthesizing BiOCl/α-Fe2O3heterostructures that significantly improve the photoresponse of BiOCl photoanodes in PEC water splitting