The perovskite solar cells, founded on lead halides, have garnered significant attention from the photovoltaic industry owing to their superior efficiency, ease of production, lightweight characteristics, and affordability. However, due to the hazardous nature of lead-based compounds, these solar cells are currently unsuitable for commercial production. In this context, a lead-free perovskite, cesium-bismuth iodide (Cs₃Bi₂I₉) is considered as a potential alternative to the lead halide-based cell due to their non-toxicity and stability, but this perovskite cannot be matched with random hole transport layer (HTL) and electron transport layer (ETL) materials compared to lead halide-based perovskite because of their crystal structure and band gap. Therefore, in this study, performance comparison of different ideal HTL and ETL materials for Cs₃Bi₂I₉ perovskite layer were studied using SCAPS-1D device simulation on the basis of open circuit voltage, short circuit current, power conversion efficiency (PCE) and fill factor (FF) as well as several novel PSC configuration models were designed that can direct for further experimental research for PSC device commercialization. Results from this investigation reveals that the maximum efficiency of 20.96 % is obtained for the configuration ITO/WS₂/Cs₃Bi₂I₉/NiO/Au with optimized parameters such as thickness 400 nm, band gap 2.1eV, absorber layer defect density 10¹² cm⁻³, donor density of ETL 10¹⁸ cm⁻³ and the acceptor density of HTL 10²⁰ cm⁻³.

The significant increase in energy consumption has facilitated a rapid increase in offensive greenhouse gas (GHG) and CO₂ emissions. The consequences of such emissions are one of the most pivotal concerns of environmental scientists. To protect the environment, they are conducting the necessary research to protect the environment from the greenhouse effect. Among the different sources of CO₂ emission, power plants contribute the largest amount of CO₂ and as the number of power plants around the world is rising gradually due to increasing energy demand, the amount of CO₂ emission is also rising subsequently. Researchers have developed different potential technologies to capture post-combustion CO₂ capture from powerplants among which membrane-based, cryogenic, absorption and adsorption-based CO₂ processes have gained much attention due to their applicability at the industrial level. In this work, adsorption-based CO₂ technologies are comprehensively reviewed and discussed to understand the recent advancements in different adsorption technologies and several adsorbent materials. Researchers and scientists have developed and advanced different adsorption technologies including vacuum swing adsorption, temperature swing adsorption, pressure swing adsorption, and electric swing adsorption, etc. To further improve the CO₂ adsorption capacity with a compact CO₂ adsorption unit, researchers have integrated different adsorption technologies to investigate their performance, such as temperature vacuum swing adsorption, pressure vacuum swing adsorption, electric temperature pressure swing adsorption, etc. Different adsorbent materials have been tested to evaluate their applicability for CO₂ adsorption and among these adsorbents, advanced carbonaceous, non—carbonaceous, polymeric, and nanomaterials have achieved much attention due to their suitable characteristics that are required for adsorbing CO₂. Researchers have reported that higher CO₂ adsorption capacity can be achieved by integrating different adsorption technologies and employing suitable adsorbent material for that system. This comprehensive review also provides future directions that may assist researchers in developing novel adsorbent materials and gaining a proper understanding of the selection criteria for effective CO₂ adsorption processes with suitable adsorbents.

Hydrogen is a source of clean energy as it can produce electricity and heat with water as a by-product and no carbon content is emitted when hydrogen is used as burning fuel in a fuel cell. Hydrogen is a potential energy carrier and powerful fuel as it has high flammability, fast flame speed, no carbon content, and no emission of pollutants. Hydrogen production is possible through different technologies by utilizing several feedstock materials, but the main concern in recent years is to reduce the emission of carbon dioxide and other greenhouse gases from energy sectors. Hydrogen production by thermochemical conversion of biomass and greenhouse gases has achieved much attention as researchers have developed several novel thermochemical methods which can be operated with low cost and high efficiency in an environmentally friendly way. This review explained the novel technologies which are being developed for thermochemical hydrogen production with minimum or zero carbon emission. The main concern of this paper was to review the advancements in hydrogen production technologies and to discuss different novel catalysts and novel CO₂-absorbent materials which can enhance the hydrogen production rate with zero carbon emission. Recent developments in thermochemical hydrogen production technologies were discussed in this paper. Biomass gasification and pyrolysis, steam methane reforming, and thermal plasma are promising thermochemical processes which can be further enhanced by using catalysts and sorbents. This paper also reviewed the developments and influences of different catalysts and sorbents to understand their suitability for continuous clean industrial hydrogen production.

CO₂ capture, use, and storage have been identified as significant strategies for reducing greenhouse gas emissions induced by the usage of fossil fuels. The current review focuses on the concepts of post-combustion capture technologies based on absorption mechanisms. Among all other developed technologies, researchers have proposed absorption as the most mature carbon capture technology for industrial-scale application. Absorption-based carbon capture can be classified into chemical and physical absorption, and researchers have developed different solvents and absorbent materials to investigate their performance in CO₂ capture. This paper comprehensively reviewed these established solvents and absorbents with their performance parameters in the CO₂ absorption approach. Besides the improvement in widely applied absorbents such as amine-based absorbents, recently, researchers have been working to develop some advanced nanomaterials such as nanofluids and nano-emulsions. This review focuses on the application of such absorption mechanisms that can contribute to capturing CO₂ in a compact, environment-friendly, and safe way. This paper also provides future research direction for further development in absorption-based CO₂ capture.

The lead halide-based perovskite solar cells have attracted much attention in the photovoltaic industry due to their high efficiency, easy manufacturing, lightweight, and low cost. However, these lead halide-based perovskite solar cells are not manufactured commercially due to lead-based toxicity. To investigate lead-free inorganic perovskite solar cells (PSCs), we investigated a novel Cs3Bi2I9-based perovskite configuration in SCAPS-1D software using different hole transport layers (HTLs). At the same time, WS₂ is applied as an electron transport layer (ETL). Comparative analysis of the various design configurations reveals that ITO/WS₂/Cs₃Bi₂I₉/PEDOT:PSS/Au offers the best performance with 20.12% of power conversion efficiency (PCE). After optimizing the thickness, bandgap, defect density, and carrier density, the efficiency of the configuration is increased from 20.12 to 24.91%. Improvement in other performance parameters such as short circuit current (17.325 mA/cm²), open circuit voltage (1.5683 V), and fill factor (91.66%) are also observed after tuning different attributes. This investigation indicates the potential application of Cs₃Bi₂I₉ as a lead-free and stable perovskite material that can contribute to improving the renewable energy sector.