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The high energy consumption and low efficiency of electrocatalysts restrict the widespread application of electrochemical water decomposition, despite being a productive method of producing industrial hydrogen. This paper proposes an oxygen vacancy-rich CuCoSnO x _500 synthesis method based on heterostructure engineering and defect introduction. The addition of various metals or anion vacancy defects modifies the properties of the catalyst and enhances surface adsorption, desorption, and electrocatalytic kinetics. The CuCoSnO x _500 exhibits 123 and 272 mV overpotential to acquire 10 and 25 mA/cm2 current density for hydrogen and oxygen evolution reactions, respectively. CuCoSnOx_500 exhibits excellent bifunctional electrocatalytic activity, with a cell voltage of 1.57 V at 10 mA/cm2 current density in 1 M KOH and 1.52 V in 1 M KOH with 0.3 M urea. The cell voltage remained constant for 40 h for the electrocatalyst at 100 mA/cm2 in a 1 M KOH electrolyte. This work presents a practical method for designing dual-purpose electrocatalysts to generate hydrogen at high current density efficiently. • A defect introduction and heterostructure engineering approach is proposed. • The CuCoSnO x catalysts exhibit 123 mV vs RHE to acquire 10 mA/cm2 for HER. • The CuCoSnO x catalysts gained 25 mA/cm2 at 272 mV vs RHE overpotential for OER. • Urea oxidation is achieved at 1.37 V vs RHE to reach a 100 mA/cm2 current. • CuCoSnO x catalysts exhibits the stability for H 2 production at 100 mA/cm2 for 40 h. [ABSTRACT FROM AUTHOR]

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 WSe 2 –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), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). WSe 2 –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. • An eco-friendly route for the development of biodegradable electrode is reported. • Electrocatalyst shows green hydrogen production and waste water treatment. • Decontamination of organic pollutants through carbon-based anode above 95%. • WSe 2 /CuO cathode exhibits overpotential of 141 mV at −10 mA cm−2. [ABSTRACT FROM AUTHOR]

In this study, practical application for the industrial-scale hydrogen evolution reaction (HER) process is established using sustainable Cu 2 CoSnS 4 embedded in paper-working electrodes. The Cu 2 CoSnS 4 is produced using a solvent-free solid-phase approach. The effect of a wide pH range of electrolytes on working electrodes for hydrogen evolution reactions is also investigated. The Cu 2 CoSnS 4 embedded paper-working electrodes exhibit goodelectrocatalytic activity for hydrogen evolution reaction with low overpotential values of 233, 310, and 261 mV vs RHE at 10 mA/cm 2 in 0.5 M H 2 SO 4 ,1 M KOH, and 1 M PBS, respectively. These designed electrodes exhibit high double-layer capacitance and electrochemical surface area for a wide pH range. In acidic, alkaline and neutral environments, the catalyst-embedded paper electrodes explicit high turnover frequencies of 2.15 s−1, 2.75 s−1, and 2.11 s−1, respectively. The temperature-dependent hydrogen evolution reaction is studied to calculate the activation energy of the cathodic electrode. Utilising chrono-amperometry for about 118 h in an acidic media, which shows that electrodes have a high degree of stability. In comparison to other previously reported work on catalyst-embedded electrodes, the Cu 2 CoSnS 4 embedded paper-working electrodes offer excellentpotential for HER activity across a wide pH range and are suitable for industrial application. • Cu 2 CoSnS 4 embedded paper working electrodes are developed for hydrogen generation. • The electrodes exhibit universal pH hydrogen evolution reaction. • Electrodes shows excellent stability upto 40hr for continuous hydrogen generation. • The electrode displays good stability at current density more than 200 mA/cm2. [ABSTRACT FROM AUTHOR]

Cu 2 CoSnS 4 , Cu 2 SnS 3 , Cu 2 CoS 4 , Co 2 SnS 3 , Cu 2 S, CoS 2 , and SnS 2 were synthesized using a one-step solvent-free solid-phase approach. The surface structure, morphology, and composition were characterized using an X-ray diffractometer (XRD), Fourier-Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Photoelectron Spectroscopy (XPS). The characterizations reveal pure phase formation and porous morphology. Further, the Hydrogen evolution reaction was performed using Cu 2 CoSnS 4 , Cu 2 SnS 3 , Cu 2 CoS 4 , Co 2 SnS 3 , Cu 2 S, CoS 2 , and SnS 2 -based electrodes. Amid all electrocatalysts, Cu 2 CoSnS 4 shows an excellent hydrogen evolution reaction with a low overpotential of −192.1 mV at −10 mA/cm2 in 0.5 M H 2 SO 4. And higher current density. Cu 2 CoSnS 4 also shows a lower Tafel slope of 98.6 mV/dec and charge transfer resistance than mono and bimetallic chalcogenide-based electrodes. The Cu 2 CoSnS 4 exhibit very good stability for ∼22 h at −10 mA/cm2 current density in 0.5 M H 2 SO 4. • Mono, bi, and tri metallic chalcogenides were synthesized by solvent-free solid-phase approach. • Cu 2 CoSnS 4 shows overpotential of −192.1 mV vs RHE at −10 mA/cm2. • Electrode displays good stability at −10 mA/cm2 current density for ∼22 h. • Volmer-Heyrovsky mechanism dominates in HER on Cu 2 CoSnS 4 -based electrode. [ABSTRACT FROM AUTHOR]

The platform used in this work, In x Mo 1-x S 2 (x = 0.05 & 0.1) nanosheets, allows for exploration of two crucial areas: remediation of the environment and optoelectronic applications. The sonochemical exfoliation approach generated the MoS 2 nanosheets. The exfoliated MoS 2 has a 2H-hexagonal lattice structure and a P 6 3 / mmc space group. The MoS 2 nanosheets' lateral shape was observed using transmission electron microscopy (TEM), and their extremely crystalline nature was verified by selected area electron diffraction (SAED). The absorption spectra of MoS₂ nanosheets show unique A and B excitonic resonances. It investigates pulse photo-response characteristics associated with dye degradation methods, emphasizing In x Mo 1-x S 2 (x = 0.05 & 0.1) efficiency in destroying dyes and enabling photocatalytic degradation, particularly with methylene blue (MB) solutions. After 120 min of exposure to light, these nanosheets are effective, breaking down organic pigments. The work also indicates a distinct pulse photoresponse in In x Mo 1-x S 2 (x = 0.05 & 0.1) Nanosheets, increasing their potential as ultrafast photodetectors for optoelectronics. Built-in electrodes produce noticeable photocurrents under 8 mV bias and polychromatic light, demonstrating a strong photovoltaic effect. The In 0.05 Mo 0.95 S 2 nanosheet-based working electrodes are significantly photovoltaic, with a photocurrent of 3.427 mA under an 8 mV bias and 100 mW/cm2 of polychromatic light. These electrodes have a remarkable peak photoresponsivity of 2.715 A/W under optimum conditions. In the end, this work demonstrates the potential of In x Mo 1-x S 2 (x = 0.05 & 0.1) nanosheets in improving optoelectronic devices and environmentally friendly solutions by revealing when dye degradation and pulse photo-response interact with one another. [ABSTRACT FROM AUTHOR]

• Flexible film of Ag decorated WSe 2 on a paper substrate for visible light (390–780 nm) photodetection and electrocatalysis for hydrogen evolution reaction (HER) • A facile handprint technique, and drop cast methods were used to fabrication of flexible electrode without the use of binders and toxic liquids. • The pave of WSe 2 crystals on paper was followed facial, cost-effective, non-toxic, environmentally friendly handprint technique. • The performance of the photodetector was tested under bending, folding, and twisting state to determine the flexibility of photodetector. • The photodetector advocates the photoresponsivity (0.43 mA/W) and a specific detectivity (2.9 × 108 Jones) at 780 nm at low bias of 1.0 V. • The HER performance of the fabricated paper-based WSe 2 /Ag electrode were carried out by linear sweep voltammetry (LSV), cyclic-voltammetry, Tafel slope, chronopotentiometry, and electrochemical impedance spectroscopy (EIS) • The WSe 2 /Ag catalyst film require an overpotential of −341 mV for HER at a current density of −10 mA/cm2, which is significantly lower than pristine WSe 2. • This study opens new opportunities for the application of the paper-based flexible devices, and convenient electrodes for electrocatalysis. Modern life is gravitating toward the light harvesting and clean energy production route because fossil fuels are becoming obsolete, which propels the researcher and scientific community to requirements of future photo-sensing and energy inventive devices based on two dimensional (2D) nanomaterials. Herein, we present the fabrication of a flexible film of Ag decorated WSe 2 on a paper substrate for visible light (390–780 nm) photodetection and electrocatalysis for hydrogen evolution reaction (HER). A facile handprint technique, and drop cast methods were used without the use of binders and toxic liquids. The photodetector advocates the photoresponsivity (0.43 mA/W) and a specific detectivity (2.9 × 108 Jones) at 780 nm at a low bias of 1.0 V. The WSe 2 /Ag catalyst film requires an overpotential of −341 mV for HER at a current density of −10 mA/cm2, which is significantly lower than pristine WSe 2. The stability of the WSe 2 /Ag electrode for a long time interval of 15 h indicates chemical robust behavior towards HER reaction. This research opens up the versatile possibility of energy harvesting, and photoconductive devices based on heterostructures. [ABSTRACT FROM AUTHOR]

• We reported the green synthesis of 2D-SnS nanosheets by microwave assisted technique. • SnS/Si heterojunction shows current rectification with ideality factor of 1.4. • Photoresponsivity of 86.2 mA/W, detectivity of 1010 Jones and EQE of 16% are realised. • Photodetector shows reproducible and stable photoresponse for prolonged time interval of 3600 s. Graphene like 2D-semiconductors of IV-VI group have captivated widespread attention in the field of opto-electronics due to their high earth abundant and distinct physical properties. Herein, we report the green synthesis of approach for 2D-SnS nanosheets by microwave assisted solvothermal process. Easy, rapid and high-yield synthesis process produced phase pure and crystalline graphene like SnS nanosheets. Subsequently, highly stable and large area photodetector based on 2D-SnS/3D-Si has been fabricated. Photodetector has shown obvious current rectifying behaviour with ideality factor of 1.4. Owing strong light matter interaction in 2D-SnS, photodetector has demonstrated highly reproducible photoresponse in broad spectral range and fast photoswitching action with response time of 150 ms. Encouragingly, photodetector has shown excellent opto-electronic stability for prolonged illumination for more than 3500 s and reproducible photoswitching for 200 cycles of periodic illumination. Overall, present finding advocates potential in fabrication of high-performance opto-electronics through green synthesis approach. [ABSTRACT FROM AUTHOR]

• WS 2 -ZnO Nanocomposite was synthesized by microwave assisted synthesis technique. • Liquid phase exfoliated WS 2 Nanosheets have band gap of 1.95 eV. • Device shows short response time and significantly enhanced detector parameter. • Device exhibits reproducible and stable photoresponse in broad spectral region. Recently, the development of opto-electronics that is integrated with ultra-broad spectral range has attracted tremendous attention. The fabricated devices should have high photoresponsivity, specific detectivity and fast switching. Herein, efforts have been applied to synthesis WS 2 -ZnO (WZO) heterostructure using high-yield microwave assisted synthesis and to fabricate large area WZO/Si heterojunction photodiode. The efforts have also been applied to find number of atomic layers in WS 2 nanosheets using Raman spectroscopy and absorption spectroscopy. The WZO/Si photodiode exhibits current rectifying behaviour (with rectification ratio 155 at 1.5 V), self-powered photodetection, improved photoresponsivity and detectivity in broad in spectral range 390–1080 nm and higher electrical stability in dark and under illumination. Present findings advocate the huge development in facile fabrication of high-performance opto-electronics over previously reported devices. [ABSTRACT FROM AUTHOR]

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 (CuCo 2 S 4) 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 CuCo 2 S 4 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 CuCo 2 S 4 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. • CuCo 2 S 4 is synthesised by hydrothermal technique for bifunctional water splitting. • CuCo 2 S 4 exhibits excellent stability in basic, acidic, neutral, and saline electrolyte. • CuCo 2 S 4 shows the bifunational water electrolysis in alkaline condition. • CuCo 2 S 4 shows advanced oxidation reaction in urea and textile dye electrolyte. [ABSTRACT FROM AUTHOR]

Heterostructures based on transition metal chalcogenides/oxides have gained significant interest in the application of electrochemical hydrogen evolution reaction (HER) due to their distinct characteristics and excellent electrocatalytic activity. Herein, we developed an earth-abundant, low-cost, and light-sensitive CuS/NiO (CSNO) heterostructure electrocatalyst via a facile co-precipitation method and fabricated it on silver-modified conducting cellulose paper for HER. Under all pH level, the performance of the visible light-sensitive HER catalyst has been examined. With the illumination of light, HER performance at all pH, which conserves energy has been seen. In basic media, the value of overpotential was improved to −290 mV vs RHE at 20 mA/cm2 under light-illuminating conditions. Similarly, with light illumination, the overpotential of the CSNO10/Ag- modified paper is reduced to −363 mV and −312 mV vs RHE in an acidic and in a near-neutral medium, respectively. In addition to that, the values of the Tafel slopes and charge-transfer resistance also decreased indicating relatively faster HER kinetics in the presence of light at all pH levels. Also, The CSNO10 electrode exhibits stability of more than 24 h in 1 M PBS with an overpotential of −368 mV vs RHE at 20 mA/cm2. The overall performance of the CuS/NiO heterostructure is a good sign to be explored it as a low-cost and efficient electrocatalyst for the large-scale production of green hydrogen (H 2). • We developed a light-sensitive CuS/NiO heterostructure electrocatalysts. • CSNO electrocatalyst shows pH universal HER performance. • CSNO shows an overpotential of −413 mV and −363 mV in light and dark. • CSNO electrocatalyst exhibits excellent stability upto 24 h. [ABSTRACT FROM AUTHOR]

Recently, large-area photodetectors fabricated with low-cost techniques have gained tremendous attention. Herein, efforts have been made to study the photodetector parameters for different concentration variations of the ZnO-WS 2 heterostructure. The device was fabricated using a drop-casting method on an ITO glass substrate with a large area channel width. It has higher electrical stability and stable photoresponse with Responsivity ∼10.6 mA/W, Detectivity ∼1011 Jones and EQE% ∼1.96% under 670 nm with an intensity of 110 μW/cm2illumination at bias 5 V, respectively. Present findings will advocate the huge development of simple, low-cost and large-area photodetectors with high performance in the nearest future. [ABSTRACT FROM AUTHOR]

• High photoresponsivity of 0.87 A/W have been achieved. • Detectivity of 1.8 × 1011 Jones and EQE of 161% are realized at −1 V bias. • Response time of found to be about 63 ms. • Photoresponse is stable for prolonged illumination of 3000 s. Two-dimensional transition metal dichalcogenides have shown promising photodetection applications in visible region due to strong light matter interaction. Herein, we have attempted to produce Ni-WS 2 nanocomposite with improved surface plasmon resonance assisted light absorption for subsequent fabrication of Ni-WS 2 /Si heterojunction. Fabricated Ni-WS 2 /Si photodiode shows obvious current rectification with 1.1 ideality factor. Photodiodes have shown obvious photovoltaic activities under illumination of visible light and remarkable photoswitching ability with high photoresponsivity of 0.87A/W, specific detectivity of 1.8 × 1011Jones and external quantum efficiency of 161% at -1 V bias. Encouragingly, photodiodes have served nicely as fast and highly stable photoswitch with response time of as low as 63 ms. Photoswitching abilities have been found to be stable even after prolonged illumination time of 2500s as well as over several cycles of periodic illumination. Overall, present finding advocates a significant development in opto-electronics due to plasmonic improvement and optimized device configuration. [Display omitted] [ABSTRACT FROM AUTHOR]

Green electronics is a trending and cost-effective method with potential application in health care monitoring and wearable electronics. We present a piezo resistive wearable pressure sensor using Polyaniline (PANI) incorporated with cellulose paper (CP) substrate. The ultralow-cost sensor is prepared by coating the sensing material on the paper using simple dip coating method. On stacking multiple PANI-CPs one upon another, the obtained flexible sensor demonstrates excellent sensitivity of 2.23 kPa−1, fast response of 70 ms and wide working range from 2 to 90 kPa. Furthermore, the sensor manifest excellent flexibility, outstanding stability up to 800 loading–unloading cycles and biodegradability. In addition, the pressure sensor can also be used for detecting rapid finger tapping. Apart from the other pressure sensors, this work mainly focusses on fabricating wearable piezo resistive sensors with low cost, facile fabricating process and shows potential for future applications in flexible wearable sensors. ga1 • Piezo resistive wearable pressure sensor was fabricate using PANI decorated on CP substrate. • The pressure sensor is prepared by coating the sensing material on to the paper using simple dip coating method. • The sensor demonstrates excellent sensitivity of 2.23 kPa−1, fast response of 70 ms and wide working range. • This work mainly focusses on fabricating wearable piezo resistive sensors with low cost, facile fabricating process. [ABSTRACT FROM AUTHOR]

• Pencil drawn graphene sheets are employed for fabrication of paper-based photodetector. • Sonochemically exfoliated WSe 2 Nanosheets were decorated on graphene film for improvement of photoresponse. • Detector exhibited excellent stability and flexibility. • Detector showed highest responsivity of 6.66 mA/W with response time of 0.8 s. We demonstrated the novel technique of ultrasonically exfoliated WSe 2 Nanosheets decorated pencil drawn multilayer Graphite coated paper-based photodetector with ultra-broad spectral activity. The present research involves the boosting of photoresponse of pencil trace-based photodetector by decoration of sonochemically exfoliated WSe 2 Nanosheets. The photodetectors exhibited good photoconducting behaviour in broad spectral range from 390 to 1080 nm with the highest responsivity of 6.66 mA/W and specific detectivity of 1.94 × 108 Jones at 670 nm and EQE of 1.25% at 390 nm. The detectors showed excellent time-resolved photoresponse with rise/decay time of 0.8/1.4 s at very low operational voltage of 0.1 to 1 V. Besides, detectors portrayed excellent flexibility at different bending angle up to 1000 bending cycles. Finally, the present study on WSe 2 Nanosheets decorated graphite photodetector advocates huge development in the field of flexible and cost-effective opto-electronics. [ABSTRACT FROM AUTHOR]

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 V x Ni 1-x O catalysts supported on three-dimensional Ni-foam scaffold for catalytic water and urea electrolysis. V x Ni 1-x O 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 °C and just 1.86 V at 60 °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 V x Ni 1-x O catalyst was measured at 1000 mA/cm2 current density for up to 17 h. • Doping energy strategy to design a vertical V x Ni 1-x O nanosheets for water and urea electrolysis. • Overpotential of 454 mV for OER and 271 mV for HER at 100 mA/cm2. • Maximum current of 1000 mA/cm2 is achieved at a cell potential of 2.3 V. • V 0.1 Ni 0.9 O catalyst shows he stability for 17 h at 1000 mA/cm2. • Urea electrolysis system has a lower cell potential of 1.418V at 100 mA/cm2. [ABSTRACT FROM AUTHOR]

In this study, we present self-supported vanadium-doped copper sulfide (Cu 2 S) 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 Cu 2 S 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 H 2 and O 2 production. DFT analyses confirms that the V-Cu s S 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 Cu 2 S electrodes for efficient water splitting in alkaline environments. [Display omitted] • Self-supported catalysts V–Cu 2 S were synthesized by hydrothermal technique. • Electrolyser generates 100 mA/cm2 current at 1.97 V in an alkaline solution. • Industrial scale water electrolysis is achieved with current of 500 mA/cm2. • DFT study shows superior HER on V–Cu 2 S due to favourable H-adsorption on S-sites. • Optimal Δ G H of 0.54 eV on V-sites in V–Cu 2 S accelerates catalytic activity. [ABSTRACT FROM AUTHOR]

• We demonstrate fabrication of fast switchable WSe 2 /Si p-n heterojunction. • Device showed highest J sc of 1.54 mA/cm2 and V oc of 0.34 V at 18 mW/cm2 power intensity. • Heterojunction exhibited broad spectral photoresponse in range from 390 to 1088 nm. • The device showed excellent response in temperature range 200 to 300 K. Propelled by the development of layered transition metal dichalcogenides, heterojunctions have captivated tremendous attention due to various excitonic mechanisms assisted strong light-matter interaction. We demonstrate liquid phase exfoliation of WSe 2 and fabrication of fast switchable WSe 2 /Si heterojunction. The heterojunction device showed obvious rectifying nature with ideality factor of 1.21 and it is explored under white illumination at power intensities varying from 5 to 18 mW/cm2. The WSe 2 /Si heterojunction photovoltaic device exhibited excellent transient photoresponse with highest responsivity of 86.11 mA/W and 23 ms response time under white light. Besides, heterojunction exhibited excellent photoresponse in broad spectral range from 390 to 1088 nm with highest photoresponsivity of 122.2 mA/W for 780 nm illumination. The device showed excellent response in temperature range 200 to 300 K. Eventually, the results advocate the huge significance of WSe 2 /Si heterojunction for photovoltaic cell and photodetection. [ABSTRACT FROM AUTHOR]

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. ReS 2 /CoS heterostructures were synthesized by two step methods involving liquid phase exfoliation of ReS 2 and hydrothermal decoration of CoS. The prepared ReS 2 /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, ReS 2 /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 ReS 2 /CoS heterostructures shows the stable electrochemical performance for HER for more than 17 h. • This article reports the facile synthesis of ReS 2 /CoS heterostructure catalyst. • Nano-interface engineering facilitates the enhanced HER and supercapacitor performance. • The specific capacitance of 663.2 F/g at 2 A/g and 643.1 F/g at scan rate 5 mV/s are achieved. • Superior HER in alkaline condition with overpotential of 187 mV at 10 mA/cm2 have been achieved. [ABSTRACT FROM AUTHOR]

Herein, we report the one-step hydrothermal synthesis of bifunctional Cr–Cu 2 S Nanoflakes supported on Cu-foam (Cr–Cu 2 S@CF) for alkaline water electrolyzer for H 2 production at an industrial scale. Vertically oriented Cr–Cu 2 S 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–Cu 2 S@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–Cu 2 S 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 Cu 2 S 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–Cu 2 S@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. • Cr–Cu 2 S@CF Nanoflakes featured a vertically oriented hexagon morphology. • Cr–Cu 2 S@CF electrocatalysts exhibit a wide range of pH values in HER activity. • Cr-doped Cu 2 S can optimize energy barriers of H 2 O dissociation and H adsorption. • Cr–Cu 2 S@CF shows excellent HER activity with overpotential of −305mV vs RHE at 1000 mA/cm2 in acidic media. [ABSTRACT FROM AUTHOR]

The design and fabrication of eco-friendly, highly sustainable and efficient, and non-noble metal-based electrodes are in high demand for the hydrogen evolution reaction (HER) in a wide pH range. Herein, we report the synthesis CuS nanoparticles and fabrication of paper-based electrodes. Robust and electrocatalytically active CuS nanoparticles shows the obvious hydrogen evolution reaction in broad pH range. Flexible, large area and binder free electrodes on paper substrate show the efficient catalytic performance in HER with small over potentials of 79, 258, 375 mV at 10 mA/cm2 in 0.5 M H 2 SO 4 , 0.5 M KOH, and 3 M NaCl, respectively. This result shows the highly active and stable electrocatalyst for HER in a wide pH range. Encouragingly, CuS/Ag/Paper electrodes advocates the significant technical development for industrial level hydrogen gas. [ABSTRACT FROM AUTHOR]