Hydrogen is a promising alternative energy source due to its high energy capacity and emission-free characteristics, fulfilling the future energy needs from non-fossil sources. This study demonstrates a rapid, in situ, and cost-effective method for hydrogen production through the hydrolysis of sodium borohydride (NaBH4) supported by tungsten trioxide (WO3) nanopellets (NPs) synthesized via microwave-assisted co-precipitation method. The WO3 NPs exhibit excellent catalytic activity, achieving a hydrogen generation rate (HGR) of 339.1 mL min(-1) g(-1) at 25 degrees C, surged to 485.8 mL min(-1) g(-1) at increasing NaBH4 solution. At an optimal pH of 8, an HGR of 340.8 mL min(-1) g(-1) is achieved, and the lowest activation energy of 27.8 kJ mol(-1) allows efficient catalysis, reaching an HGR of 935.4 mL min(-1) g(-1) at 70 degrees C. The stability of the catalyst was tested for over five cycles and a step reaction was also introduced to control the H-2 production. These results highlight the potential of WO3 NPs as a robust and economical catalyst for sustainable hydrogen production, offering significant advantages in scalability and efficiency for clean energy applications.

The development of an earth abundant, cost-effective, facile and multifunctional 3D-porous catalytic network for green hydrogen production is a tremendous challenge. Herein, we report the V-Ni3S2 self-supported catalytic network with optimized morphology grown directly on nickel foam (NF) by the one-step hydrothermal technique for water and urea electrolysis at industrial scale hydrogen generation. The morphology of Ni3S2 was modulated by doping of different concentrations of vanadium from granules to cross-linked wires to hierarchal nanosheets arrays, which is beneficial in electrochemical charge and mass transport, and generates more exposed active sites. The V-Ni3S2 catalyst requires the overpotential of 147 mV for hydrogen evolution reaction (HER). The OER and UOR half-cell reaction on V-Ni3S2 catalyst requires potential 1.57 V and 1.39 V (vs RHE), respectively to generate current 100 mA/cm2. The water electrolysis cell developed by V-Ni3S2 as both anode and cathode generates 100 mA/cm2 at cell voltage of 1.88 V in laboratory condition (1 M KOH, 25 °C) and 1.61 V at industrial condition (5 M KOH, 80 °C) and also shows considerable stability for 82 hr at current 300 mA/cm2. The urea electrolysis cell with 1 M KOH and 0.33 M urea generates 100 mA/cm2 at a cell voltage of 1.73 V, which is 150 mV less than that required for water electrolysis and demonstrate stability for 85 hr at a current of 100 mA/cm2. The results provide an innovative plan for the considerate synthesis and design of bifunctional catalysts for energy storage and water splitting.

For the circular economy approach to wastewater treatment, recycling dye-contaminated wastewater while simultaneously producing green hydrogen (H-2) is deemed appropriate. The electrodes used in the wastewater electrolysis process were made of cent percent recyclable and environmentally benign graphite rod, cellulose paper, and WSe2-CuO electrocatalyst. Anode-side breakdown of organic dyes with a 95% degradation efficiency and cathode-side generation of green hydrogen have both been accomplished simultaneously. The as-prepared electrocatalyst were analysed using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scan-ning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). WSe2-CuO electrocatalyst exhibits excellent electrochemical performance i.e. overpotential (141 mV at-10 mA cm(-2)), Tafel slope (80 mV dec(- 1)) and double layered capacitance (32.4 mF cm(-2)). Furthermore, a fast charge transfer activity, and stability of the electrocatalyst were observed through electrochemical impedance spectroscopy (EIS), and chronopotentiometry (over 20 h), respectively. A pressing need for technology development in the direction of circular sustainability may be seen in the strong demand for green hydrogen production, where the process can use industrial wastewater.

Recently, there has been a huge research interest in developing robust, efficient, low-cost, and earth-abundant materials for water and urea electrolysis for hydrogen (H2) generation. Herein, we demonstrate the facile hydrothermal synthesis of self-supported Mn-Ni3Se2 on Ni foam for overall water splitting under wide pH conditions. With the optimized concentration of Mn in Ni3Se2, the overpotential for hydrogen evolution, oxygen evolution, and urea oxidation is significantly reduced by an enhanced electrochemical active surface area. Different electronic states of metal elements also produce a synergistic effect, which accelerates the rate of electrochemical reaction for water and urea electrolysis. Owing to the chemical robustness, Mn-doped Ni3Se2 shows excellent stability for long time duration, which is important for its practical applications. A two-electrode electrolyzer exhibits low cell voltages of 2.02 and 1.77 V for water and urea electrolysis, respectively, to generate a current density of 100 mA/cm2. Finally, the prepared nanostructured Mn-Ni3Se2@NF acts as an electrocatalyst for overall water splitting under wide pH conditions and urea electrolysis for energy-saving hydrogen production and wastewater treatment.

Polymeric carbon nitride (PCN) and PCN-ZnO nanocomposites are promising candidates for catalysis, particularly for hydrogen evolution reactions (HER). However, their catalytic efficiency requires enhancement to fully realize their potential. This study aims to improve the HER performance of PCN by synthesizing PCN-ZnO nanocomposites using melamine as a precursor. Two synthesis methods were employed: thermal condensation (Method 1) and liquid exfoliation (Method 2). Method 1 resulted in a composite with a 2.44 eV energy gap and reduced particle size, with significantly enhanced performance as a bifunctional electrocatalyst for simultaneous hydrogen and oxygen production. In contrast, Method 2 produced a nanocomposite with an enhanced surface area and a minor alteration in the band gap. In alkaline electrolytes, the PCN-ZnO0.4 nanocomposite synthesized with Method 1 exhibited high HER performance with an overpotential of 281 mV, outperforming pristine PCN (382 mV) and ZnO (302 mV), along with improved oxygen evolution reaction (OER) activity. Further analysis in a two-electrode alkaline electrolyzer using PCN-ZnO0.4 nanocomposite as both the anode and cathode demonstrated its promise as a bifunctional electrocatalyst. Density functional theory (DFT) calculations explained the enhanced catalytic activity of the PCN-ZnO nanocomposite, confirming that hydrogen evolution occurs through the Heyrovsky process, consistent with experimental results. Notably, the solar-to-hydrogen (STH) efficiency of the PCN-ZnO nanocomposite was four times greater, at 21.7% compared to 5.2% for the PCN monolayer, underscoring its potential for efficient solar-driven hydrogen production. This work paves the way for future advancements in the design of high-performance electrocatalysts for sustainable energy applications.

Large-area broadband photodetectors are required due to technological advancements in the fields of optical communication, military applications, remote communication, and environmental monitoring. Additionally, wearable and flexible electronics are becoming more and more popular every day. Wearable device applications are limited by the fact that a majority of fast, broadband photodetectors are based on rigid substrates. Biodegradable photodetectors that are primarily based on paper have slow response times, typically a few seconds or even tens of seconds. In the current work, paper-based WS2:polyaniline (PANI) composite photodetectors were created to improve their performance. The WS2:PANI composite and pure WS2 were deposited on photocopy paper using a simple hand-printing technique. These hand-printed composite devices exhibit a photoresponse that is nearly 2 orders of magnitude greater than that of pure WS2 and demonstrate broadband photodetection in the wavelength range of 390-1100 nm. The devices exhibit quick response times that range from 290 to 600 ms. By examining the photoresponse for the bending configuration and that after multiple bending cycles, the device's flexibility and foldability were further investigated. Considering how quickly technology is developing these days and how much waste electronics are produced, switching to paper-based devices could help meet sustainability goals even more.

Paper -based photodetectors are gaining attention in the field of optoelectronics due to their low cost, flexibility, and eco-friendliness. The paper -based devices have applications in areas like wearable devices, environmental monitoring, and point -of -care diagnostics, where these photodetectors exhibit significant potential. In the present work, we fabricated paper -based photodetectors functionalized by WS 2 /Ti 3 C 2 T x heterostructures. These materials were characterized by X-ray diffractometer, UV -visible spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, Energy dispersive spectroscopy, and Scanning electron microscopy. We fabricated a paper -based flexible device from this WS 2 /Ti 3 C 2 T x composite using a solvent -free, easily available, and costeffective Hand -print method. We studied the I -V & I -t response of this device. The as -synthesized device shows excellent photodetection properties with a responsivity value of 3.06 mA/W, and 5.93 x 10 8 Jones specific detectivity. We further investigated the flexibility and durability of these devices. Finally, the current study supports a substantial advancement in the design of reliable, flexible, and large -area optoelectronic devices.

An advance of highly efficient nanostructured electrocatalysts based on non-noble metals for water electrolysis and urea oxidation reaction (UOR) are of great significance for urea-enriched wastewater remediation and producing hydrogen. Herein, we report VxNi1-xO catalysts supported on three-dimensional Ni-foam scaffold for catalytic water and urea electrolysis. VxNi1-xO catalysts show rapid water and urea electrolysis due to enhanced electrochemical surface area (ECSA). Most important of all, the urea oxidation reaction has a lower potential of 1.418V vs RHE as compared to oxygen evolution reaction (1.684 V vs RHE) system to generate 100 mA/cm2. Additionally, a two-electrode cell for bi-functional water electrolysis generates 100 mA/cm2 at a potential of 2.10 V at 20 degrees C and just 1.86 V at 60 degrees C temperature due to regulated the adsorption/desorption of intermediates species, enhanced charge and mass transport, and easier desorption of oxygen molecules from the anode. The stability of VxNi1-xO catalyst was measured at 1000 mA/cm2 current density for up to 17 h.

Herein, we report the one-step hydrothermal synthesis of bifunctional Cr-Cu2S Nanoflakes supported on Cu-foam (Cr-Cu2S@CF) for alkaline water electrolyzer for H2 production at an industrial scale. Vertically oriented Cr-Cu2S Nanoflakes, forming a hierarchical network is capable of efficient electrocatalytic activity owing to the high surface area, effective ions channels, and abundant redox sites. Owing to advanced morphological features, Cr-Cu2S@CF demonstrates the binder-free electrocatalytic hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at an industrial scale high current density of 500 mA/cm2. Exploiting the synergistic features, the optimized chemical composition of Cr-Cu2S delivers the geometric current density of 100 mA/cm2 at overpotential of -407 mV and -350 mV for HER and OER activity, respectively. Alloying Cr in Cu2S networks enhances oxygen desorption at the anode by decreasing the energy of adsorption of *OH intermediates, apart from enhanced HER activity due to enhanced electron density at Cu-sites. Moreover, two a two-electrode electrolyzer assembled using Cr-Cu2S@CF as an electrocatalyst at both electrodes gives current densities of 10 and 100 mA/cm2 at potentials of 1.75 V and 2.07 V, respectively.

Development of Nano-heterostructures based on transition metal chalcogenides is promising strategy to accelerate the catalytic performance for hydrogen evolution reaction (HER) and supercapacitor application. The design and development of non-noble transition metal based catalysts is required for the low-cost, efficient and earth-abundant electrodes for sustainable energy conversion and storage. ReS2/CoS heterostructures were synthesized by two step methods involving liquid phase exfoliation of ReS2 and hydrothermal decoration of CoS. The prepared ReS2/CoS heterostructures shows high performance supercapacitor applications with specific capacitance of 663.2 F/g at 2 A/g and 643.1 F/g at scan rate 5 mV/s, showing enhanced redox reaction and number of electrochemically active sites due to synergistic effect and modulated electronic structure. Additionally, ReS2/CoS heterostructures shows the superior HER performance in alkaline condition with overpotential of 187 mV at 10 mA/cm2 due to accelerated kinetics, enhanced ECSA and low charge transfer resistance. The ReS2/CoS heterostructures shows the stable electrochemical performance for HER for more than 17 h.

Herein, an advanced approach for transforming ordinary cotton-polyester fabric into a flexible and catalytic current collector is demonstrated for water and urea electrolysis for industrial-scale H2 production, addressing challenges in energy and environmental sustainability. A controlled electroless plating is adopted to deposit conducting metallic Ni-nanoparticles together with NixPy-catalytically active phase on an open macroporous framework of fabric. NiP-fabric electrodes exhibit exceptional hydrogen evolution reaction (HER) in alkaline, acidic, and in artificial Sea-water with overpotential values of 159 mV, 127 mV, and 94 mV at 10 mA/cm2 current density respectively. These electrodes also demonstrate the outstanding oxidation reaction for oxygen evolution and urea oxidation with the potential of just 1.509 V vs RHE (at 20 mA/cm2) and 1.312 V vs RHE (at 10 mA/cm2), with the in-situ formation of more active NiOOH species. A self-supported and macro-porous electrode configuration regulates the adsorption/desorption of intermediates species, enhanced charge and mass transport, and easier desorption of oxygen molecules. Finally, a two-electrode water and urea electrolyzer is constructed by NiP-fabric, which can deliver an H2-production at 100 mA/cm2 at a potential of 1.883 V and 1.611 V, respectively.

One potential method to lower the cost of electrocatalytic green hydrogen production is to use metal sulfide-based electrocatalysts in hybrid water electrolysis. This work uses a one-step hydrothermal synthesis to create copper cobalt sulphide (CuCo2S4) nanosheets for hybrid water splitting. Significant water-splitting activity was achieved using urea and organic dye (methylene blue) as supporting electrolytes to avoid delayed OER kinetics. For the KOH + urea and KOH + organic dye electrolytes, the working electrode displays an overpotential of 1.37 V against RHE and 1.30 V vs RHE, respectively, to yield a current density of 10 mA/cm2. The CuCo2S4 working electrode exhibits an overpotential of 212 mV versus RHE and 158 mV vs RHE at 10 mA/cm2 current density while monitoring hydrogen evolution reaction (HER) activity. For the KOH + organic dye electrolyte, the electrode exhibits exceptionally efficient electrocatalytic water splitting, with an overpotential of 1.50 V at a current density of 10 mA/cm2. At high current densities, the CuCo2S4 working electrode shows exceptional stability at industry standards throughout a broad pH range of basic, acidic, neutral, and saline environments. The use of several supporting electrolytes demonstrates an overall water splitting that is energy-efficient. Wastewater treatment can be accomplished through a circular economy strategy by merging the goals of environmental remediation (dye degradation) and renewable energy production (hydrogen evolution). This approach promotes sustainable growth, reduces waste, and encourages resource recovery. According to the internationally endorsed Sustainable Development Goals (SDGs), treating wastewater has the potential to help achieve 11 of the 17 SDGs.

The quest for alternative fuels has been investigated for many years owing to the storage constraints on fossil fuels and petroleum and the excessive carbon dioxide emissions following combustion. Recently, the use of hydrogen as a fuel has attracted substantial attention. Electrochemical water splitting has gained prominence as a crucial method of production that can be utilized to create clean hydrogen fuel that is sustainable, renewable, affordable, and efficient. Trifunctional electrocatalysts are substances with simultaneous catalytic activity for many electrochemical processes. Several energy conversion and storage applications require the simultaneous electrocatalytic activities of the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and an additional reaction, such as the urea oxidation reaction (UOR), which is why the design of such catalysts is of great interest. This chapter introduces the basic principles of electrochemical water splitting along with a detailed explanation of HER-, OER-, and UOR-based water-splitting mechanisms. How heteroatom doping, heterostructures, cocatalyst deposition, and surface modification can improve hydrogen generation is discussed, and the factors that affect the electrochemical performance are also examined. A promising research field with enormous potential for a range of energy conversion and storage applications is the creation of effective trifunctional electrocatalysts.

Several studies on semiconductor material-based single-band, high-performance photosensitive, and chemically stable photodetectors are available; however, the lack of broad spectral response, device flexibility, and biodegradability prevents them from being used in wearable and flexible electronics.

Scientists experience formidability in developing an advanced materials capable to withstand extreme environmental circumstances without sacrificing its fundamental properties. In this realm, solid-state devices utilizing 'metal dichalcogenide' materials offer significant advantages for cryogenic purposes, but rarely explored. In this study, thin film photodetectors (TFPDs) based on meta-materials of PdxSn1_xSe2 x Sn 1 _ x Se 2 (x=0.0, x =0.0, 0.2, 0.5) nanosheets are introduced. Nanosheets are extracted from bulk via sonochemical exfoliation to fabricate TFPDs. Novel material Pd 0.5 Sn 0.5 Se 2 grown by 50 % palladium enrichment in SnSe2 2 exhibits polymorphism comprising structural duality of hexagonal-orthorhombic phases. TFPDs based on PdxSn1_xSe2 x Sn 1 _ x Se 2 (x=0.0, x =0.0, 0.2, 0.5) nanosheets display substantial photoresponse in which TFPD functionalised by Pd 0.5 Sn 0.5 Se 2 nanosheets portrays superior photodetection. Raman peak demonstrates notable thermal-sensing through blue-shifting and sharpening under cryogenic-temperatures. Surprisingly, Pd 0.5 Sn 0.5 Se 2 nanosheets based TFPD reveals considerable photodetection, achieving 0.52 mAW_1 _ 1 responsivity at 10 K cryogenic-temperature. To the best of our knowledge, present investigation surpasses previous reports, highlighting a thin film-based photo detector that represents exceptional responsivity at 10 K cryogenic-temperature reported by us for the first time. As an outcome of present study, a TFPD based on Pd 0.5 Sn 0.5 Se 2 nanosheets emerges as advanced cryotronic material for designing next- generation cryogenic photonic devices due to its higher steadiness, excellent reproducibility and operational efficiency at cryogenic-temperature of 10 K.

Transition metal oxides (TMO), a non-noble element based oxides, establish remarkable potential in the realm of textile wastewater remediation and water splitting due to their sustainable catalytic performance. Highly functional TMO materials, in form of nanostrcutures, are of great interest owing to their robust photo and electro-catalytic activities for instituting sustainable development for the water and energy resource management framework. In the present article, we have reported catalytically active WO3 nano-pellets (NP) synthesized using microwave-assisted for photocatalytic wastewater remediation and electrocatalytic oxygen evolution reaction (OER). Promisingly, WO3 NP abetted degradation of the reactive black 5 (RB5) dye by almost 95 % in short time interval of 60 min in exposer of sun light. Present work includes the strategies to remove and observe the progression of reaction kinetics of dye degradation in neutral and alkaline media. By varying concentration of the catalyst (ranging from 250 mg/L to 1000 mg/L, in the step of 250 mg/L), we have prolifically verified that 750 mg/L turn out optimal dosage for 100% degradation in time interval of 120 min. Besides, WO3 NP has shown highest photocatalytic behaviour at 9 pH. The WO3 NP shows the electrocatalytic OER performance in an alkaline condition (1M KOH) with an overpotential of 418 mV to generate the geometric current density of 10 mA/cm² and Tafel slope of 178 mV dec⁻¹. Owing to robust nature, WO3 NP shows the almost similar photocatalytic response for ten cycles dye degradation and demonstrates the stable electrochemical charge transport for OER at 10 mA/cm2 for 50 hours.

In this study, we present self-supported vanadium-doped copper sulfide (Cu2S) electrodes as effective catalytic network for alkaline water electrolysis. The electrodes demonstrate a remarkably lower value of overpotential 375 mV for HER (hydrogen evolution reaction) and 403 mV for OER (oxygen evolution reaction) to generate 100 mA/cm2 current. A bi-functional electrolyzer incorporating these electrodes achieves a high current of 100 mA/cm2 at a cell voltage of 1.97 V. The positive influence of vanadium incorporation enhances the overall electrocatalytic activity of Cu2S and capable of generating the geometric current density of more than 500 mA/cm2 current for bi-functional electrolysis in industrial-scale alkaline electrolyte 5 M KOH at an elevated temperature of 60 °C, highlighting its potential for practical applications in renewable hydrogen production. Furthermore, the stability of electrodes was measured at different current densities at 20, 50 and 300 mA/cm2, suggesting the capabilities of electrodes for sustainable water electrolysis for green H2 and O2 production. DFT analyses confirms that the V-CusS exhibits superior performance owing to favourable H-adsorption energy on S-sites and minimum Gibb's free energy on V-sites. The study focuses on specific electrochemical performance metrics, offering insights into the promising utilization of vanadium-doped Cu2S electrodes for efficient water splitting in alkaline environments.

Advancements in technology have made it easier to construct flexible broadband photodetectors for wearable devices, improving light harvesting and detecting capabilities. This work described a new study that used bimetallic sulfide nanosheets (FeSnS) to produce flexible and broadband photodetectors on paper substrates using hand-print method. A simple, economical, one-step hydrothermal technique was employed to synthesise FeSnS materials, which were characterised using XRD, UV-Vis Spectroscopy, FESEM, EDS, XPS, and UPS. Photodetection tests found that 2-FeSnS (Fe at 2 wt%) outperformed similar work on paper-based devices, with a responsivity of 32.4 mA/W under a 470 nm incident wavelength, high specific detectivity, and a response time of 1.16 s. Durability and flexibility testing validated the robustness of the device. The use of a simple hydrothermal synthesis and hand-print fabrication method to create high-performance, eco-friendly, and flexible photodetectors is novel, expanding their potential applications in wearable electronics, environmental monitoring, and low-cost disposable sensing platforms.

Paper-based photodetectors are gaining attention in the field of optoelectronics due to their low cost, flexibility, and eco-friendliness. The paper-based devices have applications in areas like wearable devices, environmental monitoring, and point-of-care diagnostics, where these photodetectors exhibit significant potential. In the present work, we fabricated paper-based photodetectors functionalized by WS2/Ti3C2Tx heterostructures. These materials were characterized by X-ray diffractometer, UV–visible spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, Energy dispersive spectroscopy, and Scanning electron microscopy. We fabricated a paper-based flexible device from this WS2/Ti3C2Tx composite using a solvent-free, easily available, and cost-effective Hand-print method. We studied the I–V & I-t response of this device. The as-synthesized device shows excellent photodetection properties with a responsivity value of 3.06 mA/W, and 5.93 × 108 Jones specific detectivity. We further investigated the flexibility and durability of these devices. Finally, the current study supports a substantial advancement in the design of reliable, flexible, and large-area optoelectronic devices.

Improving the efficiency of energy storage and conversion requires designing electrodes with a hybrid heterostructure. Overall, a single component of MoO3 suffers from poor cycling stability and sluggish intrinsic conductivity. SnS@MoO3/MoS2 nano-heterostructure is effectively grown on 3D nickel foam using facile hydrothermal techniques to address this issue. The structure, composition, and morphology of as-prepared nano-heterostructures are characterized using X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscope, respectively. The MS-10 nano-heterostructure shows interconnected nanosheets with a self-supported porous structure. As grown, the MS-10 nano-heterostructure electrode exhibits excellent specific capacitance of 5051 Fg−1 at 2 Ag−1 with good stability. Moreover, the MS-10 electrode achieves good results in alkaline water splitting. The MS-10 nano-heterostructure presents low over potential with good stability of 12 h. This work is anticipated to advance efforts to create SnS@MoO3/MoS2 nano-heterostructure with interconnected nanosheets and self-supported porous structure, which are considered potential candidates for energy storage and conversion.