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.
The thermolytic decomposition of ammonia borane (AB) is known to proceed through the polymeric coupling reaction between –BH3 and –NH3 sites of multiple ammonia borane molecules, which results in the release of hydrogen and other by-products, e.g., ammonia, diborane and borazine.
This study proposes a cylindrical reactor design embedded with bifurcating longitudinal finned cooling tubes as the heat exchanger for an industrial‐scale metal hydride reactor system. We use Taguchi method as an optimization technique for the design parameters. The model performance was simulated with an objective of attaining the least time of absorption. The optimization involved seven control factors in an array of L 18 (2136). We observed that the number of cooling tubes, the fin length, and the number of fins are the most critical parameters for optimizing absorption time. A three‐dimensional numerical model has been developed using COMSOL Multiphysics 5.2a to predict the optimized design's hydriding performance. The absorption characteristics were studied based on the variation of pressure and heat transfer fluid temperature. At a supply pressure of 20 bars and a cooling fluid temperature of 20°C in a 50 kg system with 8 bifurcating finned cooling tubes, a hydrogen storage capacity of 1.21 wt% was achieved in 700 seconds. This paper highlights an optimized design's efficiency and operating parameter's influence to garner the best performance for rapid hydrogen charging.
Cu2ZnSnTe4 was synthesized using mechano-chemical route from its elemental precursors. A homologous series of kesterite light absorber material Cu2ZnSnX4 (X: S, Se, Te) can be used for realization of multi-junction solar cells.
In this paper, we report the effect of adding Zr + V or Zr + V + Mn to TiFe alloy on microstructure and hydrogen storage properties. The addition of only V was not enough to produce a minimum amount of secondary phase and, therefore, the first hydrogenation at room temperature under a hydrogen pressure of 20 bars was impossible. When 2 wt.% Zr + 2 wt.% V or 2 wt.% Zr + 2 wt.% V + 2 wt.% Mn is added to TiFe, the alloy shows a finely distributed Ti2Fe-like secondary phase. These alloys presented a fast first hydrogenation and a high capacity. The rate-limiting step was found to be 3D growth, diffusion controlled with decreasing interface velocity. This is consistent with the hypothesis that the fast reaction is likely to be the presence of Ti2Fe-like secondary phases that act as a gateway for hydrogen.
Borazine is a by-product often encountered in the thermal decomposition of ammonia borane, which leads to an inescapable hindrance towards sustainability and cost effectiveness. In this study, a low cost, low surface area clay mineral, bentonite, was modified and introduced as a support material. Bentonite (42.4 m2 g−1) revealed decomposition characteristics comparable to previously reported high surface area (usually 700–1000 m2 g−1) support materials. In addition, borazine formation from bentonite supported ammonia borane was observed to be completely eliminated. Extensive size strain analysis (Williamson–Hall and Warren–Averbach) indicated that the crystalline parameters were observed to be a considerable factor affecting the dehydrogenation reaction along with the high surface area. However, using in situ XRD and MS characterization, the supported decomposition was attributed to a facile pathway, which was dominated by DADB formation. The proposed pathway justifies the borazine elimination and more steady hydrogen release from AB.
About Me
Centre for Research in Nanotechnology and Sciences Indian Institute of Technology Bombay Powai, Mumbai – 400076, India
Centre for Research in Nanotechnology and Sciences Indian Institute of Technology Bombay Powai, Mumbai – 400076, India