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The naked-eye detection of hazardous pollutants through simple and cost-effective techniques is of great interest to the scientific community and related stakeholders in analytical science. The present study emphases the development of a stimuli-responsive probe by encountering sophisticated techniques for the detection of environmental pollutants. Herein, highly swellable and fluorescent-WTR-CDs-loaded HB-Alg/Gel@WTR-CDs was fabricated through a simple extrusion dripping method. The fluorescent WTR-CDs-loaded composite hydrogel showed rapid (within 10-15 min) naked-eye detection with high selectivity and sensitivity towards Cr 6+ and Mn 7+ ions over other metal ions. The developed probe had a linear detection range of 0-10 μg mL -1 with a detection limit of 0.28 μg mL -1 and 0.30 μg mL -1 for Cr 6+ and Mn 7+ ions, respectively. Interestingly, the hydrogel-based fluorescent sensor enabled on-site naked-eye detection of real water samples with good recovery. Additionally, the recyclability and reusability approach were employed for the removal of model pollutant dyes with Alg/Gel-carbon, which was synthesized using spent hydrogel beads after sensing. The present study demonstrates the tremendous potential applications of HB-Alg/Gel@WTR-CDs for simple, low-cost and fast visual detection of environmental pollutants. According to the analytical greenness evaluation (AGREE), the developed analytical method is green with an AGREE score of 0.81 and an ecofriendly circular-economy approach.

In this study, high-quality γ-In 2 Se 3 thin films were successfully deposited on p-Si substrates via the RF sputtering technique. Structural characterization using XRD and Raman spectroscopy confirmed the formation of the hexagonal γ-phase of In 2 Se 3 film. FESEM analysis revealed the presence of small, homogeneous, and well-defined grains in the prepared γ-In 2 Se 3 film. EDS analysis confirmed the stoichiometric composition (∼ 2:3) of the In 2 Se 3 films. XPS further validated the presence of In, Se, and Si elements in the deposited films. Band gap analysis using UV-visible spectroscopy yielded a value of 1.96 eV for the γ-In 2 Se 3 film. Integration of γ-In 2 Se 3 with p-type Si enhanced photoresponsivity of 47.9 mA/W, photosensitivity of 282, and photo detectivity of 8.45 × 10 10 Jones. The self-powered γ-In 2 Se 3 /p-Si heterojunction-based photodetector exhibited rapid rise time attributed to the type II band alignment structure, facilitating efficient electron-hole pair separation and minimizing recombination. Furthermore, humidity and light intensity-dependent photodetector properties of γ-In 2 Se 3 /p-Si heterojunction photodetector were also investigated. An increase in photocurrent from 271 to 291 µA was observed with rising humidity levels, indicating the device's sensitivity to humidity variations. Furthermore, light intensity dependence studies revealed a linear relationship between photocurrent and incident light intensity, demonstrating the device's reliable response across various illumination levels.

Water polluted by toxic chemicals due to waste from chemical/pharmaceuticals and harmful microbes such as E. Coli bacteria causes several fatal diseases; and therefore, water filtration is crucial for accessing clean and safe water necessary for good health. Conventional water filtration technologies include activated carbon filters, reverse osmosis, and ultrafiltration. However, they face several challenges, including high energy consumption, fouling, limited selectivity, inefficiencies in removing certain contaminants, dimensional control of pores, and structural/chemical changes at higher thermal conditions and upon prolonged usage of water filter. Recently, the advent of 2D materials such as graphene, BN, MoS 2 , MXenes, and so on opens new avenues for advanced water filtration systems. This review delves into the nanoarchitectonics of 2D materials for water filtration applications. The current state of water filtration technologies is explored, the inherent challenges they face are outlines, and the unique properties and advantages of 2D materials are highlighted. Furthermore, the scope of this review is discussed, which encompasses the synthesis, characterization, and application of various 2D materials in water filtration, providing insights into future research directions and potential industrial applications., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

In this study, a novel heterogeneous catalyst (Fe 3 O 4 @β-CD@Pd) has been developed by the deposition of palladium nanoparticles on the β-cyclodextrin-functionalized surface of magnetic Fe 3 O 4 . The catalyst was prepared by a simple chemical co-precipitation method and characterized extensively by using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-optical emission spectrometry (ICP-OES) analyses. Herein, the applicability of the prepared material was evaluated for the catalytic reduction of environmentally toxic nitroarenes to the corresponding anilines. The catalyst Fe 3 O 4 @β-CD@Pd showed excellent efficiency for the reduction of nitroarenes in water under mild conditions. A low catalyst loading of 0.3 mol % Pd is found to be efficient for reducing nitroarenes in excellent to good (99-95%) yields along with high TON values (up to 330). Nevertheless, the catalyst was recycled and reused up to the 5th cycle of reduction of nitroarene without any loss of significant catalytic activity., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Cu 2 ZnSnS 4 (CZTS) thin films have attracted considerable attention as potential candidates for photovoltaic absorber materials. In a vacuum deposition technique, a sputtering stacked metallic layer followed by a thermal process for sulfur incorporation is used to obtain high-quality CZTS thin films. In this work, for fabricating CZTS thin films, we have done a 3LYS (3 layers), 6LYS, and 9LYS sequential deposition of Sn/ZnS/Cu metal stack ( via . metallic stacked nanolayer precursors) onto Mo-coated corning glass substrate via . RF-sputtering. The prepared thin films were sulfurized in a tubular furnace at 550 °C in a gas mixture of 5% H 2 S + 95% Ar for 10 min. We further investigated the impact of the Sn/ZnS/Cu metal stacking layers on the quality of the thin film based on its response to light because metal inter-diffusion during sulfurization is unavoidable. The inter-diffusion of precursors is low in a 3-layer stack sample, limiting the fabricated film's performance. CZTS films with 6-layer and 9-layer stacks result in an improved photocurrent density of ∼38 μA cm -2 and ∼82 μA cm -2 , respectively, compared to a 3-layer sample which has a photocurrent density of ∼19 μA cm -2 . This enhancement can be attributed to the 9-layer approach's superior inter-diffusion of metallic precursors and compact, smooth CZTS microstructure evolution., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Layered bismuth triiodide (BiI 3 ) is a 2D material that has emerged as an ideal choice for optical sensors. Although BiI 3 has been prepared using vacuum-based deposition techniques, there is a dearth of research studies on synthesizing this material using chemical route. The present work uses a facile spin coating method with varying rotation speeds (rpm) to fabricate BiI 3 material thin films for photodetection applications. The structural, optical, and morphological study of BiI 3 thin films prepared at 3000-6000 rpm were investigated. XRD analysis indicates formation of BiI 3 films and revealed that BiI 3 has a rhombohedral crystal structure. FESEM analysis showed that BiI 3 films prepared at different rpm are homogeneous, dense, and free from cracks, flaws, and protrusions. In addition, films show an island-like morphology with grain boundaries having different grain sizes, micro gaps, and the evolution of the granular morphology of BiI 3 particles. The UV spectroscopy and photoluminescence analysis revealed that BiI 3 films strongly absorb light in the visible region of spectra with a high absorption coefficient of ∼10 4 cm -1 , have an optical band gap of ∼1.51 eV. A photodetector was realised using fabricated BiI 3 film obtained at an optimum spin speed of 4000 rpm. It showed rapid rise and decay times of 0.4 s and 0.5 s, a responsivity of ∼100 μA W -1 , external quantum efficiency of 2.1 × 10 -4 %, and detectivity of ∼3.69 × 10 6 Jones at a bias voltage of 0 V. Our results point towards a new direction for layered 2D BiI 3 materials for the application in self-biased photodetectors., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

ZrBi 2 Se 6 nanoflower-like morphology was successfully prepared using a solvothermal method, followed by a quenching process for photoelectrochemical water splitting applications. The formation of ZrBi 2 Se 6 was confirmed by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The estimated value of work function and band gap were found to be 5.5 and 2.26 eV measured using diffuse reflection spectroscopy and ultraviolet photoelectron spectroscopy, suggesting the potential candidate for water splitting. The highest current density of 9.7 μA/cm 2 has been observed for the ZrBi 2 Se 6 photoanode for the applied potential of 0.5 V vs SCE. The flat-band potential value was -0.46 V, and the 1.85 nm width of the depletion region is estimated from the Mott-Schottky (MS) analysis. It also reveals that the charge carrier density for the ZrBi 2 Se 6 nanoflowers is 4.8 × 10 15 cm -3 . The negative slope of the MS plot indicates that ZrBi 2 Se 6 is a p-type semiconductor. It was observed that ZrBi 2 Se 6 nanoflowers had a high charge transfer resistance of ∼730 kΩ and equivalent capacitance of ∼40 nF calculated using electrochemical impedance spectroscopy (EIS) measurements. Using chronoamperometry, the estimated rise time and decay time were 50 ms and 0.25 s, respectively, which reveals the fast photocurrent response and excellent PEC performance of the ZrBi 2 Se 6 photoanode. Furthermore, an attempt has been made to explain the PEC activity of ZrBi 2 Se 6 nanoflowers using an energy band diagram. Thus, the initial results on ZrBi 2 Se 6 nanoflowers appear promising for the PEC activity toward water splitting., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)