Abstract:
An appealing strategy in the direction of circular chemistry and sustainable nitrogen exploitation is to efficiently convert NOx pollutants into low-toxic products and simultaneously provide crop plants with metabolic nitrogen. This study demonstrates that such a scenario can be realized by a defect- and morphology-coengineered Ni-Fe-layered double hydroxide (NiFe-LDH) comprising ultrathin nanosheets. Rich oxygen vacancies are introduced onto the NiFe-LDH surface, which facilitate charge carrier transfer and enable photocatalytic O2 activation into superoxide radicals (•O2-) under visible light. •O2- on NiFe-LDH thermodynamically oxidizes NO into nitrate with selectivity over 92%, thus suppressing dangerous NO2 emissions. By merit of abundant mesopores on NiFe-LDH ultrathin nanosheets bearing a high surface area (103.08 m2/g), nitrate can be readily stored without compromising the NO oxidation reactivity or selectivity for long-term usage. The nitrate species can be easily washed off the NiFe-LDH surface and then enriched in the liquid form as easy-to-use chemicals.
摘要:
循环化学和可持续氮开发方向上的一个吸引人的策略是有效地将NOx污染物转化为低毒性产物,同时为作物提供代谢氮。这项研究表明,这种情况可以通过包含超薄纳米片的缺陷和形态共同工程的Ni-Fe-层状双氢氧化物(NiFe-LDH)来实现。富氧空位被引入到NiFe-LDH表面,其促进电荷载体转移并使光催化O2在可见光下活化为超氧自由基(·O2-)。•NiFe-LDH上的O2-将NO热力学氧化为硝酸盐,选择性超过92%,从而抑制危险的NO2排放。由于NiFe-LDH超薄纳米片上具有丰富的中孔,具有高表面积(103.08m2/g),硝酸盐可以很容易地储存,而不会损害NO的氧化反应性或长期使用的选择性。硝酸盐物质可以容易地从NiFe-LDH表面洗掉,然后作为易于使用的化学品以液体形式富集。