Bowen Ren,Qiuyan Jin,Yinwei Li,Yan Li,Hao Cui,Chengxin Wang
Though transition-metal-based materials have emerged as the most promising alternatives to Pt-based electrocatalysts in hydrogen evolution reaction (HER), only a few of them (Fe-, Co-, Ni-, W-, and Mo-based materials) are used as efficient HER electrocatalysts, while others are generally considered as HER-inactive materials with poor activities. Here, a theory-guided experiment is carried out to activate titanium dioxide as a new efficient HER electrocatalyst. First-principles simulations indicate that the hydrogen adsorption free energy could be optimized through tuning the structural and electronic properties of TiO2. Then Cu-doped amorphous TiO2 is successfully prepared based on the theoretical results. The activated TiO2 expectedly shows excellent HER performance with a low overpotential of 92 mV at 10 mA cm–2 in alkaline media, which is far superior to that of the crystalline TiO2 (over 400 mV). The origin of HER activity is further investigated in detail. The corrugation of the amorphous surface helps stabilize the adsorbed water molecule, crucial for the water dissociation of the Volmer step. The Cu doping can strengthen the orbital hybridization of H1s and O2p favoring the hydrogen adsorption/desorption and improve the electrical conductivity. Our work highlights the great potential of traditionally inactive materials in HER electrocatalysis and helps deepen our understanding of the catalytic mechanism.
Yi Liu,Qingguo Feng,Wei Liu,Qian Li,Yuchao Wang,Biao Liu,Lirong Zheng,Wei Wang,Lin Huang,Limiao Chen,Xiang Xiong,Yongpeng Lei
For electrocatalytic hydrogen evolution reaction (HER) in alkaline media , it is urgently needed to accelerate the generation of H*. Here, using Se doped phosphides inside nitrogen doped carbon (skin-core structure) as catalysts, the HER performance in alkaline electrolyte was improved. The overpotential of 261 mV at 400 mA cm −2 was among the top level reported so far. Based on the combination of experimental results and density functional theory (DFT) calculations, the interior CoSe phase generated by Se modification provides faster charge transfer from the inner to carbon layer , facilitating the rate-determining step (Volmer). Also, the needle-like nanowire array facilitates the H 2 desorption at a large current density. Furthermore, a solar-to-hydrogen efficiency up to 10.2% was demonstrated. This work may provide an effective strategy to boost the reaction kinetics via accelerating interfacial charge transfer ability of electrocatalysts .
危险品化学品经营许可证（带存储）