The poor electronic conductivity of metal-organic framework (MOF) materials hinders their direct application in the field of electrocatalysis in fuel cells. Herein, we proposed a strategy of embedding carbon nanotubes (CNTs) during the growth process of MOF crystals, synthesizing a metalloporphyrin-based MOF catalyst TCPPCo-MOF-CNT with a unique CNT-intercalated MOF structure. Physical characterization revealed that the CNTs enhance the overall conductivity while retaining the original characteristics of the MOF and metalloporphyrin. Simultaneously, the insertion of CNTs generated adequate mesopores and created a hierarchical porous structure that enhances mass transfer efficiency. X-ray photoelectron spectroscopic analysis confirmed that the C atom in CNT changed the electron cloud density on the catalytic active center Co, optimizing the electronic structure. Consequently, the E_1/2 of the TCPPCo-MOF-CNT catalyst under neutral conditions reached 0.77 V (vs. RHE), outperforming the catalyst without CNTs. When the TCPPCo-MOF-CNT was employed as the cathode catalyst in assembling microbial fuel cells (MFCs) with Nafion-117 as the proton exchange membrane, the maximum power density of MFCs reached approximately 500 mW·m^-2.

Development of methodologies for fabrications of nanostructured materials that provide control over their microstructural features and compositions represents a fundamental step in the advancement of technologies for productions of materials with well-defined functional properties. Pulse electrolysis, a top-down electrochemical approach, has been demonstrated to be a viable method for producing nanostructured materials with a particular efficacy in the synthesis of tin oxides. This method allows for significant control over the composition and shape of the resulting tin oxides particles by modifying the anionic composition of the aqueous electrolyte, obviating the need for additional capping agents in the synthesis process and eliminating the requirement for high-temperature post-treatments. The composition and microstructural characteristics of these oxides are found to be contingent upon the differing stabilities of tin fluoride and chloride complexes, as well as the distinct mechanisms of interaction between chloride and fluoride anions with an oxidized tin surface, which is influenced by the varying kosmotropic/chaotropic nature of these anions. The composition and microstructural characteristics of the obtained dispersed tin oxides would thus determine their potential applications as an anode material for lithium-ion batteries, as a photocatalyst, or as an oxyphilic component of a hybrid support for a platinum-containing electrocatalyst.

Graphitic carbon nitride (g-C₃N₄) exhibits great mechanical as well as thermal characteristics, making it a valuable material for use in photoelectric conversion devices, an accelerator for synthesis of organic compounds, an electrolyte for fuel cell applications or power sources, and a hydrogen storage substance and a fluorescence detector. It is fabricated using different methods, and there is a variety of morphologies and nanostructures such as zero to three dimensions that have been designed for different purposes. There are many reports about g-C₃N₄ in recent years, but a comprehensive review which covers nanostructure dimensions and their properties are missing. This review paper aims to give basic and comprehensive understanding of the photocatalytic and electrocatalytic usages of g-C₃N₄. It highlights the recent progress of g-C₃N₄ nanostructure designing by covering synthesis methods, dimensions, morphologies, applications and properties. Along with the summary, we will also discuss the challenges and prospects. Scientists, investigators, and engineers looking at g-C₃N₄ nanostructures for a variety of applications might find our review paper to be a useful resource.