One Step Method of Structure Engineering Porous Graphitic Carbon Nitride for Efficient Visible-Light Photocatalytic Reduction of Cr(VI)
One Step Method of Structure Engineering Porous Graphitic Carbon Nitride for Efficient Visible-Light Photocatalytic Reduction of Cr(VI)
复制标题
结构工程多孔石墨碳氮化物高效可见光光催化还原 Cr(VI) 的一步法
DOI：
10.1016/j.jmst.2020.09.008
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发表时间：
2020
影响因子：
10.9
通讯作者：
Guofeng Guan
中科院分区：
文献类型：
--
作者：
Xueru Chen;Yin Zhang;Dashui Yuan;Wu Huang;Jing Ding;Hui Wan;Wei-Lin Dai;Guofeng Guan
采用镍辅助一步热聚合法制备了多孔g-C3N4纳米片（PCN）。泡沫镍 (Ni) 与氨 (NH3) 反应产生的氢气 (H2) 决定了 PCN 的结构和性能。在PCN形成过程中，H2的参与不仅增大了层间距，而且增大了比表面积，使更多的活性位点暴露出来。此外，H2促进纳米片中孔隙的形成，有利于光子通过层状结构的传输，提高可见光的吸收效率。值得注意的是，所获得的 PCN 比纯 g-C3N4 具有更好的 Cr(VI) 光催化还原效率。 PCN 的反应速率常数 (k) (0.013 min−1) 大约是裸 g-C3N4 (0.007 min−1) 的两倍。此外，还探讨了含Cr(VI)溶液的初始pH和浓度对Cr(VI)去除效率的影响。基于自由基清除剂和光电化学表征的实验，提出了一种可能的光催化机理。
Porous g-C3N4nanosheets (PCN) were prepared by the nickel-assisted one-step thermal polymerization method. Hydrogen (H2) which was produced by the reaction between nickel (Ni) foam and ammonia (NH3) defined the structure and properties of PCN. During the formation of PCN, the participation of H2not only enhanced the spacing between layers but also boosted the specific surface area that more active sites were exposed. Additionally, H2promoted pores formation in the nanosheets, which was beneficial to the transfer of photons through lamellar structure and improved the absorption efficiency of visible light. Remarkably, the obtained PCN possessed better Cr(VI) photocatalytic reduction efficiency than pure g-C3N4. The reaction rate constant (k) of PCN (0.013 min−1) was approximately twice that of bare g-C3N4(0.007 min−1). Furthermore, the effects of original pH and concentration of Cr(VI)-containing solution on removal efficiency of Cr(VI) were explored. A possible photocatalytic mechanism was proposed based on the experiments of radical scavengers and photoelectrochemical characterizations.