【摘要】 为解决赤铁矿（α-Fe₂O₃）和石墨相氮化碳（g-C₃N₄）光催化活性低的问题，设计了一种采用液固混合-焙烧制取α-Fe₂O₃/g-C₃N₄复合光催化剂的方法。通过在可见光照射下光催化还原Cr（Ⅵ）实验研究合成的α-Fe₂O₃/g-C₃N₄复合物的光催化性能，并通过光电化学性能测试及能带结构分析探究其光催化活性增大的原因。结果表明：所合成的α-Fe₂O₃/g-C₃N₄复合物具有显著优于α-Fe₂O₃和g-C₃N₄的光催化活性，其光催化还原Cr（Ⅵ）的反应速率常数（k）为0.026 min^-1,分别是g-C₃N₄ (k=0.004 min^-1)的6.5倍和α-Fe₂O₃(k=0.003 min^-1)的8.7倍；α-Fe₂O₃/g-C₃N₄复合物为Ⅰ型异质结，能有效提高光生空穴与电子的分离及转移效率，是导致其光催化活性升高的原因。所设计的合成方法简单易行、成本低且合成的α-Fe₂O₃/g-C₃N₄复合物光催化还原Cr（Ⅵ）性能好，为Cr（Ⅵ）废水处理开发了一种有应用潜力的可见光催化剂。更多还原

【Abstract】 In order to solve the problem of low photocatalytic activity of hematite（α-Fe₂O₃） and graphite-phase carbon nitride（g-C₃N₄）, α-Fe₂O₃/g-C₃N₄ composite photocatalyst was designed and prepared by liquid-solid mixing-calcining method. The photocatalytic performance of the as-synthesized α-Fe₂O₃/g-C₃N₄ composite was studied via photocatalytic reduction of Cr（Ⅵ） under visible-light irradiation, and the reasons for its increased photocatalytic activity were investigated by photoelectrochemical property tests and energy band structure analysis. The results demonstrate that the α-Fe₂O₃/g-C₃N₄ composite has notably superior photocatalytic activity than α-Fe₂O₃ and g-C₃N₄. The reaction rate constant（k） of Cr（Ⅵ） reduction on α-Fe₂O₃/g-C₃N₄ composite is 0.026 min^-1, which is 6.5 times than that on g-C₃N₄(k=0.004 min^-1) and 8.7 times than that on α-Fe₂O₃(k=0.003 min^-1). α-Fe₂O₃/g-C₃N₄ composite is of type-Ⅰ heterojunction, which can effectively improve the separation and transfer efficiency of photogenerated holes and electrons, and this is the reason for the improvement of its photocatalytic activity. The designed synthesis method is facile, practicable, low-cost, and the synthesized α-Fe₂O₃/g-C₃N₄ composite possesses good performance in photocatalytic reduction of Cr（Ⅵ）, so this study has developed a potential visible-light photocatalyst for the treatment of Cr（Ⅵ） wastewater.更多还原