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Mineral carbonation in aqueous solutions presents a pragmatic avenue for tackling the challenges associated with carbon capture, utilisation, and storage, particularly in limiting global temperature rise to 1.5 °C for climate change mitigation. The urgency to engineer the removal of atmospheric CO2 has driven the exploration of innovative methods for direct conversion into valuable products, with a specific emphasis on calcite as a promising approach for carbon dioxide sequestration. This investigation focuses on the biomimetic strategy of emulating the catalytic activity of carbonic anhydrase by synthesizing a zinc-based metal-organic framework. The MOF, synthesized with Zinc as the central metal coordinated by 1,2,3-benzene tricarboxylic acid, displays noteworthy structural adaptability, diversity, and an extensive surface area. The characterisation of synthesised materials through UV DRS, XRD, XPS, FTIR, SEM, and Raman analyses corroborates its structural features. A comparative study with a Nickel-based MOF (Ni-BTC-MOF) underscores the advantages of zinc over nickel in CO2 mineralisation experiments. Remarkably, Zn-BTC-MOF demonstrates superior catalytic activity, reusability, solvent compatibility, and thermal stability compared to Ni-BTC-MOF. The Zn-BTC-MOF catalyst achieves a mineralisation yield of 25 mg, comparable with the reported results for natural carbonic anhydrase (34.92 mg) and imidazole-carbonic anhydrase (21.55 mg). The Zn-BTC-MOF catalyst displays exceptional reusability, maintaining CO2 mineralisation activity across over a broad pH and temperature range. These findings underscore the potential of Zn-BTC-MOF as an effective biomimetic catalyst for carbon dioxide mineralisation, holding promising applications in carbon capture and utilization technologies. [ABSTRACT FROM AUTHOR]

In the present investigation, we report the formation of a metal–metal oxide (Zn/ZnO) nanoscale heterointerfac with concomitant hydrogen generation. The synthesis process is simple and involves the optical illumination of Zn nanoparticles (Zn(NP)) suspended in water. The concomitant hydrogen (H2) evolution during synthesis was found to be linear, and it is dependent on the growth of the Zn/ZnO nano interface. The progressively increasing amount of ZnO relative to Zn(NP) was a limiting factor in H2 evolution. Two different Zn/ZnO nanoscale heterointerfaces were created and samples were extracted at two different stages of the illumination process. The first sample, extracted from the most reactive illumination phase and named Zn(NP)/ZnO-R, had the highest hydrogen evolution reaction (HER) rate. The second sample, extracted from a less reactive illumination phase and named Zn(NP)/ZnO-S, had a lower HER rate. These in situ (solar light-induced) samples were characterized by XRD, HRTEM, and other methods. The optoelectronic features and the photoelectrochemical (PEC) investigations showed the optimal light-harvesting ability of Zn(NP)/ZnO-R and the effective separation of photoexcited charge carriers, leading to remarkable HER performance. During the visible-light-induced (in situ) conversion of Zn(NP) to Zn(NP)/ZnO-R, a concurrent HER rate of 1115 μmol h−1 was observed. Indeed, the photocurrent density value of the Zn(NP)/ZnO-R catalyst is significantly higher than that of Zn(NP)/ZnO-S, pristine Zn(NP), and ZnO. Thus, this study provides new insights into the optimal fabrication of the Zn(NP)/ZnO interface for PEC application with concomitant solar hydrogen generation. [ABSTRACT FROM AUTHOR]

In many developing and developed countries, presence of arsenite [As(III)] more than 10 ppb in groundwater is reported. Many people use the arsenic contaminated groundwater for drinking purposes, which is hazardous to human health. Hence need to be removed below the permissible level before use for drinking purpose. In this batch study, IBOA was used as an adsorbent to remove As(III) from water. From experimental data, optimal values for the dose of IBOA, time of contact and pH were found to be 1.0g/L, 24 hrs and 7.0, respectively. In this paper, ANN was applied to the various parameters and found that the results are satisfied in time study. Best fitting was found in dose study and initial concentration study where as in pH study, the ANN results and experimental results are in good agreement. In effect of coexisting ions study, ANN could not map in all cases and not shown the satisfactory results. From experimental data, it is proved that IBOA having good potential for removal of As(III) from groundwater. [ABSTRACT FROM AUTHOR]

Pure phase of CeFeO 3 perovskite was synthesized by using a modified microwave-assisted method and was systematically studied by photo-electrochemical (PEC) investigations for water splitting reaction. Characterization studies confirm the formation of crystalline orthorhombic single phase perovskite structure with space group Pbnm and having agglomerated sponge-like morphology with nano size grains. DRS shows broad absorption in UV–Visible region, while tauc plot also inferred estimated band gap of 1.9 eV. The photo-activity of their screen printed thin film was analyzed by PEC studies, which includes photocurrent, EIS spectra, MS-plot, J-V plots. On illumination, EIS analysis of CeFeO 3 reveals improved charge transfer at interfaces of semiconductor/electrolyte. The photocurrent density difference of CeFeO 3 was increased to 6.9 mA cm −2 at an applied bias of 1.5 V vs (Ag/AgCl). PEC H 2 evolution shows significant cumulative hydrogen rate of 12.3 μmol cm −2 h −1 . All these results reveal that the microwave-synthesized CeFeO 3 is a potential candidate for PEC application under the visible light illumination. [ABSTRACT FROM AUTHOR]