Concern over water contamination by per/polyfluoroalkyl substances (PFAS) has highlighted the lack of effective treatment approaches. Photocatalysis offers advantages of using ambient conditions for reaction, air as the oxidant, and light as the energy source, but identifying photoactive materials is challenging. Herein, we report that boron nitride (BN) degrades PFOA upon irradiation with 254 nm light. The ability of BN to degrade PFOA photocatalytically has previously been unreported and is unexpected, because its band gap is too large for light absorption. On the basis of scavenger results, we suggest that PFOA degrades in the presence of BN via a hole-initiated reaction pathway similar to the TiO₂ case and involves superoxide/hydroperoxyl and hydroxyl radicals. We surmised that defects allow BN to absorb in the UVC range and to photogenerate reactive oxygen species. Sealed batch studies indicated BN was ∼2 and ∼4 times more active than TiO₂, before and after ball milling the material, respectively. BN can be reused, showing no decrease in activity over three cycles. BN was active for the photocatalytic degradation of GenX, another PFAS of concern. These findings present fresh opportunities for materials design and for the re-evaluation of other wide band gap semiconductors for PFAS photocatalytic degradation.

中文翻译：

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氮化硼上高效光催化PFOA的降解

对全氟/多氟烷基物质（PFAS）对水的污染的关注突出表明，缺乏有效的处理方法。光催化具有以下优势：使用环境条件进行反应，使用空气作为氧化剂，使用光作为能源，但是识别光敏材料具有挑战性。在本文中，我们报道氮化硼（BN）在254 nm光照射下会降解PFOA。BN光催化降解PFOA的能力以前没有报道过，这是出乎意料的，因为它的带隙对于光吸收来说太大了。根据清除剂的结果，我们建议在存在BN的情况下，PFOA会通过类似于TiO ₂的空穴引发反应途径降解情况，涉及超氧化物/氢过氧基和羟基自由基。我们推测缺陷允许BN在UVC范围内吸收并光生活性氧。密封批次研究表明，在球磨材料之前和之后，BN的活性分别是TiO _2的约2倍和约4倍。BN可以重复使用，表明在三个周期内活动没有减少。BN对GenX（另一个关注的PFAS）的光催化降解具有活性。这些发现为材料设计以及对PFAS光催化降解的其他宽带隙半导体的重新评估提供了新的机会。