Highly efficient catalytic technologies are urgently needed to remove pharmaceutical pollutants from water. In this work, the preparation, characterization, and photocatalytic performance of an earth‐abundant Ni‐based heterogeneous catalyst featuring highly dispersed Ni species over nanosheets of carbon nitride are reported. The absence of any metallic nickel phase has been confirmed by spectrometric analyses, unveiling the NiN environment for the metal centers and attaining synergistic interfacial carrier transfer via NNiN coordination. By combining advanced characterizations with kinetic investigations, it is demonstrated that these newly formed isolated single atoms of Ni act as a bridge, facilitating faster electron transfer, increasing the charge density on Ni, and reducing the photocarrier transfer barrier. Compared to literature precedents, this substantially enhances the degradation of gemfibrozil, a model pharmaceutical pollutant found in wastewater, reducing the formation of toxic benzenic byproducts during photooxidation. This effect, which is not observed over conventional nanoparticle‐based materials, discriminates the role of single‐atom and nanoparticle‐based catalysis during degradation of pollutants. This work opens new avenues in designing selective and earth‐abundant photocatalysts for advanced oxidation processes, showing the importance of atom coordination to control the surface and catalytic properties of single‐atom materials.

No abstract

No abstract

Nowadays, most of the hydrogen is obtained from fossil fuels. At the same time, the effort and resources dedicated to the development of sustainable hydrogen manufacturing processes are rapidly increasing to promote the energy transition toward renewable sources. In this direction, a potential source of hydrogen could be hydrogen sulfide, produced as a byproduct in several processes, and in particular in the oil extraction and refinery operations. Methane reforming using H2S has recently attracted much interest for its economic and environmental implications. Its conversion, in fact, provides a viable way for the elimination of a hazardous molecule, producing a high-added value product like hydrogen. At the same time, some of the still open key aspects of this process are the coke deposition due to thermal pyrolysis of methane and the process endothermicity. In this work, the methane reforming with H2S by co-feeding sulfur is investigated through a detailed thermodynamic analysis as a way to alleviate the critical aspects highlighted for the process. A parametric analysis was conducted to assess the best thermodynamic conditions in terms of pressure, temperature, and feed composition. Changing the sulfur, H2S, and methane feed composition can enhance the system by improving the hydrogen production yield, reducing the carbon and sulfur deposition, increasing the H2S removal efficiency, and reducing the necessary thermal duty.

No abstract