Modulation engineering ofin situcathodic activation of FeP(x)based on W-incorporation for the hydrogen evolution reaction

摘要

In situelectrochemical activation as a new pretreating method to adjust electrocatalytic performance attracts extensive attention. However, the activation mechanisms of electrocatalysts are still ambiguous. Herein, we propose a facile modulation strategy ofin situcathodic activation of FeP(x)based on W-incorporation (W-FePx/IF) for the hydrogen evolution reaction (HER). The activated W-FeO(x)with obvious surface reconstruction demonstrates the role of W-incorporation for driving the cathodic activation of FePx, which suggests the larger surface area and more active sites. In fact, W incorporation can not only accelerate the cathodic activation process but also act as the adsorption sites for H(ad)to form the synergistic effect with FeO(x)for water dissociation. The obtained W-FeOx/IF exhibits greatly enhanced HER activity featuring decreased overpotential from 237.7 to 154.0 mV at 100 mA cm(-2), which may be ascribed to W-FeO(x)with double catalytic active sites after cathodic activation. Additionally, the modulation effects of cathodic activation can be exactly achieved by changing electrochemical parameters such as CV cycles. W-FeOx/IF also shows excellent long-term stability for at least 100 h at 100 mA cm(-2). This modulation engineering based on metal doping is expected to provide inspiration for the understanding of the cathodic activation process for efficient electrocatalysts.