Mn3O4 Nanozyme Coating Accelerates Nitrate Reduction and Decreases N2O Emission during Photoelectrotrophic Denitrification by Thiobacillus denitrificans-CdS
Mn3O4 Nanozyme Coating Accelerates Nitrate Reduction and Decreases N2O Emission during Photoelectrotrophic Denitrification by Thiobacillus denitrificans-CdS
复制标题
Mn3O4 纳米酶涂层可加速脱氮硫杆菌-CdS 光电反硝化过程中硝酸盐还原并减少 N2O 排放
DOI：
10.1021/acs.est.0c02709
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发表时间：
2020-09-01
影响因子：
11.4
通讯作者：
Zhou, Shungui
中科院分区：
文献类型：
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作者：
Chen, Xiangyu;Feng, Qinyuan;Zhou, Shungui
生物半导体是将太阳能转化为化学能的高效系统。然而，不可避免的活性氧（ROS）的存在严重恶化了生物半导体的性能。本工作通过简单、快速、经济的方法成功构建了一种纳米酶包被Mn3O4的生物半导体——反硝化硫杆菌-硫化镉（T. denitrificans-CdS@Mn3O4）。Mn3O4涂层后，活性氧被大大消除；在光电营养反硝化过程中，羟基自由基、超氧自由基和过氧化氢的浓度分别降低了90%、77.6%和26%。与T.反硝化菌- cds相比，T. denitrificans-CdS@Mn3O4的硝酸盐还原率高28%，氧化亚氮排放量低78% （68 h）。此外，Mn3O4涂层有效地维持了生物半导体中CdS的微生物活力和光化学活性。重要的是，在PEDeN过程中没有观察到滞后期，这表明Mn3O4涂层不会影响T.反硝化菌- cds的代谢。立即分解和物理分离是保护生物半导体免受Mn3O4活性氧损伤的两种可能方法。该研究提供了一种简单的方法来保护生物半导体免受不可避免地产生的活性氧的毒性，并将有助于未来开发更稳定和高效的生物半导体。
Biosemiconductors are highly efficient systems for converting solar energy into chemical energy. However, the inevitable presence of reactive oxygen species (ROS) seriously deteriorates the biosemiconductor performance. This work successfully constructed a Mn3O4 nanozyme-coated biosemiconductor, Thiobacillus denitrificans-cadmium sulfide (T. denitrificans-CdS@Mn3O4), via a simple, fast, and economic method. After Mn3O4 coating, the ROS were greatly eliminated; the concentrations of hydroxyl radicals, superoxide radicals, and hydrogen peroxide were reduced by 90%, 77.6%, and 26%, respectively, during photoelectrotrophic denitrification (PEDeN). T. denitrificans-CdS@Mn3O4 showed a 28% higher rate of nitrate reduction and 78% lower emission of nitrous oxide (at 68 h) than that of T. denitrificans-CdS. Moreover, the Mn3O4 coating effectively maintained the microbial viability and photochemical activity of CdS in the biosemiconductor. Importantly, no lag period was observed during PEDeN, suggesting that the Mn3O4 coating does not affect the metabolism of T. denitrificans-CdS. Immediate decomposition and physical separation are the two possible ways to protect a biosemiconductor from ROS damage by Mn3O4. This study provides a simple method for protecting biosemiconductors from the toxicity of inevitably generated ROS and will help develop more stable and efficient biosemiconductors in the future.