The development of environmental-benign, efficient, and durable Mn based catalysts is of great importance for remediation of organic pollutants. In this study, a series of cryptomelane-type octahedral molecular sieve (OMS-2) and carbon nanofibers (CNFs) nanocomposites (OC) were synthesized by a facile refluxing approach under different conditions, and the catalytic activity was evaluated for Acid Orange 7 degradation under neutral conditions via peroxymonosulfate activation. It was revealed that the composites were more efficient than the pure OMS-2 and CNFs, due to the higher amounts of Mn(II) and Mn(III) species and the synergistic effects between OMS-2 and CNFs. The OC catalysts presented long-term stability without the leaching of Mn ions during seven consecutive cycles. Radical scavenger and EPR experiments indicated that the low valent Mn species in the composites were oxidized by PMS to produce sulfate radicals to degrade dyes. However, the structure and performance of OC were influenced significantly by CNFs dosage and refluxing time. Under a high CNFs ratio or a long refluxing time, OMS-2 was damaged and lost its catalytic activity completely. This study provides important implications for turning of the valence of Mn species in manganese oxides, and widens the practical applications of the manganese oxides/ carbon materials in wastewater treatment.

开发对环境有益，高效且耐用的Mn基催化剂对于补救有机污染物具有重要意义。本研究通过简便的回流方法在不同条件下合成了一系列隐甲烷型八面体分子筛（OMS-2）和碳纳米纤维（CNFs）纳米复合物（OC），并评价了其对酸性橙7的催化活性。在中性条件下通过过一硫酸盐活化。结果表明，由于Mn（II）和Mn（III）的含量更高，以及OMS-2和CNF之间的协同作用，复合材料比纯OMS-2和CNF更为有效。OC催化剂表现出长期的稳定性，并且在七个连续的循环中均没有Mn离子的浸出。自由基清除剂和EPR实验表明，复合材料中的低价Mn物质被PMS氧化，生成硫酸根，从而降解染料。但是，氯化萘的用量和回流时间对OC的结构和性能有显着影响。在高CNFs比或长时间回流的情况下，OMS-2被破坏并完全失去催化活性。这项研究为改变锰氧化物中锰物种的价态提供了重要意义，并拓宽了锰氧化物/碳材料在废水处理中的实际应用。OMS-2被破坏并完全失去催化活性。这项研究为改变锰氧化物中锰物种的价态提供了重要意义，并拓宽了锰氧化物/碳材料在废水处理中的实际应用。OMS-2被破坏并完全失去催化活性。这项研究为改变锰氧化物中锰物种的价态提供了重要意义，并拓宽了锰氧化物/碳材料在废水处理中的实际应用。