Oxygen evolution reaction (OER) is a key reaction for many renewable energy storage and conversion techniques. Developing efficient non-precious metal-based electrocatalysts for OER has attracted increasing attention. Herein is reported a strategy to fabricate hierarchical cobalt borate/Ti C T MXene (Co-B /Ti C T ) hybrid through fast chemical reactions at room temperature. This interesting hierarchical structure of Co-B /Ti C T hybrid is beneficial for exposing more active sites, improving mass diffusion, and charge-transfer pathways for electrochemical reaction. Moreover, a strong interaction between Co-B and Ti C T ensures efficient charge transfer and facilitates the electrostatic attraction of more anionic intermediates for a fast redox process. Consequently, the hierarchical Co-B /Ti C T hybrid shows extraordinary OER catalytic activity to deliver a current density of 10 mA cm at an overpotential of 250 mV, and a Tafel slope of about 53 mV dec .

MoS2 and its derivates have been regarded as a promising catalyst for the hydrogen evolution reaction (HER), and their edge sulfur sites are key factors for the HER performance. Here, we develop a facile strategy to grow nonstoichiometric molybdenum sulfide (MoS x ) with more active sulfur sites on porous N-doped graphene (MoS x @CN). Experiments demonstrate that the introduction of porous N-doped graphene not only facilitates the fast transfer of charge and the efficient infiltration of the electrolyte but the N dopants could be used as the nucleation sites for MoS x to possess more active bridging S2 2– sites. Consequently, the obtained MoS x @CN catalyst possesses an outstanding HER activity, which shows an overpotential of 256 mV at 100 mA cm–2 with a Tafel slope of 49 mV dec–1. This study provides a new strategy to optimize transition metal dichalcogenide-based catalysts for energy-related applications.