Carbonized Wood Decorated with Cobalt-Nickel Binary Nanoparticles as a Low-Cost and Efficient Electrode for Water Splitting

Using an inexpensive and eco-friendly wood substrate, herein, a one-step calcination method is developed to deposit Co-Ni binary nanoparticles into aligned wood channels and an effective carbonized wood (CW) electrode (termed as Co/Ni-CW) is fabricated. Well distributed Co-Ni nanoparticles are achieved by the coordination bonds between the hydroxyl groups on wood matrix and soaked metal cations. Subsequently, high-temperature calcination promotes the nucleation of Co-Ni nanoparticles and the formation of CW. With the uniform distribution of Co-Ni nanoparticles and porous wood structure, not only is a high active surface area, but also the electron and mass diffusion pathways are enhanced. Thus, the as-prepared Co/Ni-CW affords the current density of 10 mA cm(-2) at low overpotentials of 330 and 157 mV for oxygen and hydrogen evolution, respectively. Remarkably, when the wood-based bifunctional electrocatalyst is used as both the anode and cathode, a low cell voltage of 1.64 V is required to reach the current density of 10 mA cm(-2). Compared with most substrates used in bifunctional electrocatalysts, the abundance, low cost, eco-friendliness, and easy operation of wood-based catalysts allow for an active and scalable electrode for water splitting and many other energy storage devices.

Automated summary

Using an inexpensive and eco-friendly wood substrate, a one-step calcination method was developed to deposit Co-Ni binary nanoparticles into aligned wood channels, resulting in the fabrication of an effective carbonized wood electrode. The uniformly distributed Co-Ni nanoparticles in the porous wood structure provide a high active surface area, enhancing the electron and mass diffusion pathways for efficient electrochemical reactions.