Institute of Inorganic Chemistry , RWTH Aachen University , Landoltweg 1 , D-52056 Aachen , Germany.
AC2T Research GmbH, Viktor-Kaplan-Straße 2 C , AT-2700 Wiener Neustadt , Austria.
Langmuir. 2018 Apr 3;34(13):3845-3852. doi: 10.1021/acs.langmuir.8b00149. Epub 2018 Mar 23.
CuWO is a photoanode candidate in neutral pH, and manganese-based oxygen evolution reaction electrocatalysts are of high interest due to their low price and low toxicity. Considering the unexplored chemistry of transition-metal carbodiimides/cyanamides for the PEC water oxidation, we investigated MnNCN as an electrocatalyst for CuWO under AM 1.5G illumination in potassium phosphate electrolyte (pH 7). Surface functionalization of CuWO photoanodes with MnNCN increased the photocurrent from 22 to 30 μA cm at 1.23 V vs RHE. Complementary structural analysis by means of XRD and XPS revealed that MnNCN forms a core-shell structure MnNCN@MnPO in phosphate electrolyte and mimics a manganese phosphate electrocatalyst. As such, the surface chemistry of MnNCN significantly differs from previous studies on the cobalt analogue (CoNCN). A separately prepared MnNCN electrode developed a small but detectable photocurrent due to photogenerated holes inside the semiconducting carbodiimide core of the MnNCN@MnPO structure.
CuWO 是中性 pH 值下的光阳极候选材料，而基于锰的氧析出反应电催化剂由于其价格低廉和低毒性而备受关注。考虑到过渡金属碳二亚胺/氰胺在 PEC 水氧化中尚未被探索的化学性质，我们研究了 MnNCN 作为 CuWO 在 AM 1.5G 光照下在磷酸钾电解质（pH 7）中的电催化剂。通过在 CuWO 光阳极表面功能化 MnNCN，在 1.23 V vs RHE 时将光电流从 22 μA cm 增加到 30 μA cm。通过 XRD 和 XPS 进行的补充结构分析表明，MnNCN 在磷酸盐电解质中形成 MnNCN@MnPO 的核壳结构，并模拟了一种锰磷酸盐电催化剂。因此，MnNCN 的表面化学性质与先前关于钴类似物（CoNCN）的研究明显不同。由于 MnNCN@MnPO 结构中半导体碳二亚胺核内的光生空穴，单独制备的 MnNCN 电极产生了较小但可检测的光电流。
