Albeit surface reconstruction of precatalysts for alkaline oxygen evolution reaction (OER) is extensively studied, the dynamic structure evolution and true active phase in neutral media remain largely unexplored. Here, the activation behaviors in neutral and alkaline media are comparatively studied using NiMoO₄ as a model precatalyst. Our results reveal that, when electrochemically activated in harsh alkaline conditions, NiMoO₄ undergoes rapid and complete reconstruction with the formation of a considerable NiOOH active phase. On the other hand, direct activation in neutral media only results in weak reconstruction with a thin NiOOH layer on NiMoO₄ surface. Accordingly, the electrode oxidized in basic electrolyte yields a superior OER performance compared to that directly treated mild pH condition. Our study deepens the understanding of the neutral water oxidation reaction, which provides insightful guidelines for further development of efficient electrocatalysts for neutral water electrolysis with self-reconstruction.

The novel coronavirus (COVID-19) control and prevention brings new challenges and opportunities to college physics experiment teaching. Online teaching by teachers and home-based experiments by students are the new characteristics of experimental teaching in this special period. This paper mainly introduces a series of home DIY grating diffraction experiments. Using a laser pen as the light source, and using a steel ruler, CD and LCD screen as the grating materials, the transmission and reflection grating diffraction in one-dimensional or two-dimensional can be realized. By using common and simple equipment commonly used in daily life, one can observe a wealth of grating diffraction phenomenon and do measurement with considerable accuracy, and accordingly, students can not only fully feel the fun of searching and collecting handy parts for non-lab experiments and but deepen the understanding of diffraction. Therefore, grating diffraction series experiments are very suitable for home and offline experiments.