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The design and exploration of high-efficiency and low-cost electrode catalysts are of great significance to the development of novel energy conversion technologies. In this work, metal and nonmetal heteroatoms co-doped biphasic tungsten-based chalcogenide heterostructured catalyst (Co-WS

To fabricate high-quality catalysts with abundant active sites, a series of transition-metal-modified nitrogenous carbon catalysts (Ta-NOC, Nb-NOC, and Nb/Ta-NOC) was successfully fabricated via pyrolysis and ion exchange. Owing to the high conductivity and ion transport capacity of its unique nitrogen-carbon structure, and synergistic effect of dual-metal active sites on modulating electronic structure, Nb/Ta-NOC catalyst exhibited an excellent catalytic performance and a remarkable electrochemical stability in triiodide reduction reaction (IRR) and hydrogen evolution reaction (HER). Nb/Ta-NOC catalyst achieved an ideal conversion efficiency of 8.45% for IRR in solar cells, which was higher than that of Pt electrode (7.63%). Furthermore, Nb/Ta-NOC catalyst exhibited a small overpotential of 145 mV at a current density of 10 mA·cm-2 and a Tafel slope of 77 mV dec-1 for HER. This work provided a new approach for the rational design of the active-sites-rich electrocatalysts for energy conversion applications.

Developing electrocatalysts with excellent catalytic performance and superior durability for hydrogen evolution reaction (HER) remains a challenge. Herein, metal-nitrogen sites (M–Nx, M = Ni and Cu) are successfully implanted into zeolitic imidazolate zinc framework (ZIF-8)-derived nitrogen-doped porous carbon (ZIF/NC) to prepare Ni-ZIF/NC and Cu-ZIF/NC electrocatalysts for the HER. These M–Nx active sites significantly enhanced the electrocatalytic activities of Ni-ZIF/NC and Cu-ZIF/NC. Metal Ni acted as a catalyst for catalysis of Ni-ZIF/NC to form carbon nanotubes-like structures, which provided convenient ion transmission pathways. Owing to its special morphology and an increased number of defects, Ni-ZIF/NC displayed superior electrocatalytic activity in the HER compared to those of Cu-ZIF/NC and ZIF/NC. In an alkaline environment, Ni-ZIF/NC exhibited an overpotential at the current density of 10 mA cm−2 (η10) of 163.0 mV and Tafel slope of 85.0 mV dec−1, demonstrating an electrocatalytic property equivalent to that of Pt/C. In an acidic environment, Ni-ZIF/NC yielded a η10 of 177.4 mV and Tafel slope of 83.9 mV dec−1, which were comparable to those of 20 wt.% Pt/C. Moreover, Ni-ZIF/NC and Cu-ZIF/NC also exhibited superior stabilities in alkaline environments. This work offers a valuable strategy for controlling the morphology and implanting M–Nx active sites into carbon for designing novel catalysts for use in alternative new energy applications.

Fabrication of efficient non-precious electrocatalysts with hierarchical nanostructures and the desired compositions is highly desirable to enhance the catalytic activity and stability for hydrogen evolution reaction (HER) and triiodide reduction reaction (IRR). This work proposes a zeolitic imidazolate framework (ZIF) template-based strategy to generate sulfide embedded in nitrogen-doped carbon with a hierarchical 2D/3D nanocage structure. ZIF-67, as a sacrificial template, is first etched to form 2D/3D NiCo layered double hydroxide/2-Methylimidazole (NiCo LDH/MeIm) and then converted to CoNi

Designing efficient nanohybrid electrocatalysts with advanced structure is of great essential for energy conversion devices. Herein, a multi-dimensional hierarchical strategy is proposed to design melamine sponge-derived sulfur and nitrogen co-doped tetrapod carbon (SNTC) supported cobalt-nickel telluride (CoTe

： Developing high-performance and low-cost catalysts for replacing Pt-based catalysts is a significant challenge for solar cells and water splitting applications. In this work, a bifunctional hybrid catalyst of MnTa2O6@MPC (MPC: mesh-like bio-based porous carbon) was synthesized, using a co-precipitation approach. Benefiting from the high specific surface area (332.743 m2 g-1), integrating the merits of the electrical conductivity of MPC, the outstanding electrocatalytic ability of MnTa2O6, and the synergistic effect between MnTa2O6 and MPC, the catalytic activity of MnTa2O6@MPC was significantly enhanced. To boost the photovoltaic performance of dye-sensitized solar cells, a novel Cu2+/Cu+ redox mediator and dye (Y123, D35) were adopted for replacing the traditional I3-/I- redox mediator and N719 dye, respectively. The resulting advanced solar cell with the Cu2+/Cu+ redox mediator based on the MnTa2O6@MPC counter electrode catalyst exhibited a photovoltage of ~0.88 V, and cell efficiencies of 3.41% and 1.92% for the D35 and Y123 dye systems, respectively, which are respectively 16% and 8% higher than that of Pt. MnTa2O6@MPC also exhibited significant catalytic ability for hydrogen production, yielding a small overpotential of 141.9 mV at a current density of 10 mA cm-2 and a small Tafel slope of 105.0 mV dec-1 in an alkaline medium. This work provides promising guidance for designing bifunctional hybrid electrocatalysts for high-performance new energy devices.