Scientists worldwide have been inspecting hydrogen production routes and showing the importance of developing new functional materials in this domain. Numerous research articles have been published in the past few years, which require records and analysis for a comprehensive bibliometric and bibliographic review of low-carbon hydrogen production. Hence, a data set of 297 publications was selected after filtering journal papers published since 2010. The search keywords in the Scopus Database were "green hydrogen" and "low carbon hydrogen production and materials". The data were analyzed using the R Bibliometrix package. This analysis made it possible to determine the total annual publication rate and to segregate it by country, author, journal, and research institution. With a general upward trend in the total number of publications, China was identified as the leading country in research on the subject, followed by Germany and Korea. Keyword analysis and the chronological evolution of several important publications related to the topic showed the focus was on water splitting for low-carbon H₂ production. Finally, this review provides future directions for technologies and functional materials for low-carbon hydrogen production.

Objective: The objective of this study is the development of the basic guidelines for blending green hydrogen with natural gas and transporting it through the gas pipelines of a natural gas distribution company. The characteristics of consumption, legislation and materials used in the company's network were considered. In addition, data from recent research in the area was also selected to support specific actions so that this objective is achieved in a technically sustainable way, respecting technical knowledge and standards available internationally. Method: In this scenario, a study of the feasibility of enriching natural gas distributed by a gas distribution company in the region of the city of Fortaleza with green hydrogen is presented. In addition, data from recent research in the area was also selected to support specific actions so that this objective is achieved in a technically sustainable way, respecting technical knowledge and standards available internationally. Results and Discussion: Based on current legislation and a series of technical references, it is currently recommended to add levels of up to 2% in branches where natural gas is used for vehicular and industrial glass and ceramic applications and can increase up to 3% in other extensions. The maximum concentration may reach 10% in the medium term after detailed fatigue resistance studies or adaptation of pipes with internal polymer jackets. Research Implications: The interest in replacing fossil fuels for decarbonization purposes has motivated research into a series of alternatives, among which hydrogen stands out as a possible vector or energy carrier for high-efficiency systems with oxidation free of carbon emissions. carbon. Introducing renewable hydrogen into natural gas distribution networks stabilizes the demand for production of this gas, in addition to alleviating the costs and risks associated with building a dedicated facility. Originality/Value: This study contributes to the literature related to the study of green Hydrogen. The relevance and value of this research are evidenced by the results obtained.

Multilayerfilms with kesterite are often used for energy conversion, such as photoanode for hydrogen production and manufacture of photovoltaic solar cells. It is due to the fact that they are efficient and use small amounts of material. Cu₂ZnSnS₄, known as CZTS, is a semiconductor belonging to the kesterite group, which can be obtained in powder or film form. Copper, zinc, tin and sulfide are precursors commonly used in the synthesis of the CZTS. The methodology used to synthesize films is crucial for the success of the final product. It is essential to develop methods which can lower synthesis costs, which can also lower the solar cell costs, for example. Besides the costs, the method must be efficient and increase the efficiency of the devices in which they are employed, and must not be harmful to the environment. This study developed a methodology to synthesize CZTS. It was used in this work dimethyl sulfoxide, copper acetate, tin chloride, zinc chloride and thiourea as precursors. The layers of the film above the glass substrate were characterized with X-ray diffraction, ultraviolet and visible analyses, scanning electron microscopy, fourier transform infrared spectroscopy and X-ray fluorescence spectroscopy. The results absorbance peaks between 300 and 400 nm, in the ultraviolet range, reflectance around 40% in the visible, transmittance reaching above 50% and 50%, and direct band gap about 1.42 ± 0.02 eV associated with the kesterite. The characterization methods proved to be efficient to identify the presence of the kesterite phase at films produced by overlapping layers.

Dye sensitized solar cells (DSSC) are a third-generation solar cell, composed of dye, photoanode, a counter electrode and a redox electrolyte. The sensitized dye affects the overall efficiency of the cell by the amount of excited dye inside the cell. This work investigated the effect that different time’s absorption of N719 dye causes on a TiO2/ZnO based DSSC. The longer dye sensitized time helped to increase the short-circuit current density and the efficiency of the cell, with optimum time of six hours, for current and four hours for efficiency.