In the present study, we adopt an easy and cost-effective route for preparing Cu₂ZnSnS₄ (CZTS)-absorber nanoparticles by a mechanochemical method using non-toxic and environmentally benign solvents (butanol, methyl ethyl ketone, and ethanol). The gram-scale synthesis of absorber nanoparticles was achieved in a non-hazardous, zero-waste process without using high-vacuum equipment. The effects of annealing and Na incorporation on the properties of spin-coated CZTS thin films were scrutinized. The deposited samples showed kesterite crystal structure and single phase. The morphological results revealed an improvement in the surface morphology after annealing. The optical bandgaps of the thin films lied in the range of 1.50–1.57 eV with p-type nature. Finally, photovoltaic devices were fabricated, and their cell performance parameters were studied. An efficiency of 0.16% was observed. The present study provides a potential route for the cost-effective fabrication of CZTS-based photovoltaic devices.

Surface area and surface active sites are two important key parameters in enhancing the gas sensing as well as photocatalytic properties of the parent material. With this motivation, herein, we report a facile synthesis of Reduced Graphene Oxide/Tungsten Oxide RGO/WO₃ hierarchical nanostructures via simple hydrothermal route, and their validation in accomplishment of improved H₂S sensing and highly efficient solar driven photo-degradation of RhB Dye. The self-made RGO using modified Hummer’s method, is utilized to develop the RGO/WO₃ nanocomposites with 0.15, 0.3 and 0.5 wt% of RGO in WO₃ matrix. As-developed nanocomposites were analyzed using various physicochemical techniques such as XRD, FE-SEM, TEM/HRTEM, and EDAX. The creation of hierarchic marigold frameworks culminated in a well affiliated mesoporous system, offering efficient gas delivery networks, leading to a significant increase in sensing response to H₂S. The optimized sensor (RGO/WO₃ with 0.3 wt% loading) exhibited selective response towards H₂S, which is ~ 13 times higher (R_a/R_g = 22.9) than pristine WO₃ (R_a/R_g = 1.78) sensor. Looking at bi-directional application, graphene platform boosted the photocatalytic activity (94% degradation of Rhodamine B dye in 210 min) under natural sunlight. The RGO’s role in increasing the active surface and surface area is clarified by the H₂S gas response analysis and solar-driven photo-degradation of RhB dye solution. The outcome of this study provides the new insights to RGO/WO₃ based nanocomposites’ research spreadsheet, in view of multidisciplinary applications.

Tin monoselenide (SnSe) nanoparticles (NPs) have great potential to replace the conventional absorbers used in the fabrication of thin film solar cells. However, studies pertaining to the synthesis and fabrication of SnSe NPs-based solar cells are still lacking. This study presents an eco-friendly synthesis of SnSe NPs by a chemical precipitation method in a short reaction time of 10 min. The effect of different reducing agents (such as NaOH, ethylenediamine, Na₂SO₃, and NaBH₄) on the reactivity of a Se-precursor and phase formation of SnSe NPs was investigated in detail. Our study indicated that the reaction between Sn²⁺ ions complexed by ascorbic acid and Se²⁻ ions provided by the reduction with NaBH₄ resulted in the formation of single phase SnSe NPs. For the first time, a SnSe NPs thin film inorganic solar cell with the device structure of SLG/Mo/SnSe NPs/CdS/i-ZnO/Al:ZnO/Ni/Ag was fabricated and tested, which showed an efficiency of 0.43%.

A schematic illustration of PANI–MnMoO₄synthesis for overall water splitting is demonstrated with excellent electrocatalytic activity and stability.