Xiaofeng Li

Developing efficient and stable non-precious metal catalysts for the oxygen evolution reaction (OER) is crucial for addressing global energy challenges. In this work, unlike conventional powder-based composites that rely on polymeric binders, we engineered a binder-free, three-dimensional (3D) self-supported electrocatalyst by directly incorporating cobalt (Co) and nitrogen-rich graphitic carbon nitride (g-C₃N₄) onto a nickel foam (NF) substrate. Through a facile in situ calcination approach, a series of nitrogen-containing OER electrocatalysts, denoted as CoCN/NF-x (x = 40–100%), were synthesized. The in situ thermal treatment facilitated the possible Co-N coordination or strong electronic interactions between the nitrogen atoms of the g-C₃N₄ framework and the Co centers. This unique structural design significantly reduces interfacial contact resistance, prevents active site aggregation, and builds a highly conductive architecture. Electrochemical OER tests revealed that the catalyst with 80% Co content (CoCN/NF-80) exhibited superior electrocatalytic activity. At a current density of 10 mA cm⁻², it achieved a low overpotential of 263 mV in 1.0 M KOH. Moreover, it showcased a remarkably small Tafel slope of 61 mV dec⁻¹, indicating highly favorable OER kinetics. After a 12 h chronoamperometric test, the overpotential increased by only 11%, and post-test characterizations confirmed a favorable surface reconstruction rather than structural degradation, demonstrating promising stability for extended operations. The synthetic strategy developed here can be extended to the preparation of various electrocatalytic materials, contributing to energy-efficient fabrication and sustainable development goals.

Constructing highly efficient electrocatalysts is vital to enhance oxygen evolution reaction (OER) performance at industrially relevant current densities. Herein, three-phase coupled Ni₃S₂/r-NiS/h-NiS composites are grown in situ on Ni foam (NNSN/NF) via a one-step solvothermal approach. The as-prepared composites need overpotentials of only 377 mV, 451 mV and 476 mV at 1000 mA cm⁻² for the OER in alkaline freshwater, simulated seawater and seawater, respectively. In addition, the optimized catalyst exhibited long-term durability at 300 mA cm⁻². Our work clarifies designing and preparing cost-effective Ni-based sulfide electrocatalysts for the OER in alkaline freshwater/simulated seawater/seawater under industrially relevant current densities.

The specific capacity of urchin-like NiCo₂S₂ is 1352 F g⁻¹ at a current density of 1 A g⁻¹. The NiCo₂S₄//AC ASC device provides high energy density at a power density of 2025 W kg⁻¹. The capacitance retention of NCS-1.5//AC is 81.98% after 10 000 cycles of charging and discharging.

The α-Fe ₂ O ₃ /In ₂ O ₃ heterojunctions derived from a bimetal–organic framework of an InFc MOF, endows a high sensitivity (86) to 100 ppm cyclohexane at a working temperature of 225 °C, in the top set for similar types of sensors.

CoMoO ₄ /MoO ₃ @CuCoNi–S is prepared by hydrothermal and electrodeposition methods. It offers promising supercapacitor properties.

Searching for low-cost and highly-efficient oxygen reduction reaction (ORR) catalysts is crucial to the large-scale application of fuel cells. Herein, by means of density functional theory (DFT) computations, we proposed a new class of ORR catalysts by doping the CrS₂ monolayer with non-metal atoms (X@CrS₂, X = B, C, N, O, Si, P, Cl, As, Se, and Br). Our results revealed that most of the X@CrS₂ candidates exhibit negative formation energy and large binding energy, thus ensuring their high stability and offering great promise for experimental synthesis. Moreover, based on the computed free energy profiles, we predicted that N@CrS₂ exhibits the best ORR catalytic activity among all considered candidates due to its lowest overpotential (0.41 V), which is even lower than that of the state-of-the-art Pt catalyst (0.45 V). Remarkably, the excellent catalytic performance of N@CrS₂ for ORR can be ascribed to its optimal binding strength with the oxygenated intermediates, according to the computed linear scaling relationships and volcano plot, which can be well verified by the analysis of the p-band center as well as the charge transfer between oxygenated species and catalysts. Therefore, by carefully modulating the incorporated non-metal dopants, the CrS₂ monolayer can be utilized as a promising ORR catalyst, which may offer a new strategy to further develop eligible electrocatalysts in fuel cells.