DeSario Paul A, Gordon Wesley O, Balboa Alex, Pennington Ashley M, Pitman Catherine L, McEntee Monica, Pietron Jeremy J
Surface Chemistry Branch, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States.
U.S. Army Combat Capabilities Development Command Chemical Biological Center, 8198 Blackhawk Road, Aberdeen Proving Ground, Maryland 21010, United States.
ACS Appl Mater Interfaces. 2021 Mar 17;13(10):12550-12561. doi: 10.1021/acsami.0c21988. Epub 2021 Mar 3.
Multifunctional composites that couple high-capacity adsorbents with catalytic nanoparticles (NPs) offer a promising route toward the degradation of organophosphorus pollutants or chemical warfare agents (CWAs). We couple mesoporous TiO aerogels with plasmonic Cu nanoparticles (Cu/TiO) and characterize the degradation of the organophosphorus CWA sarin under both dark and illuminated conditions. Cu/TiO aerogels combine high dark degradation rates, which are facilitated by hydrolytically active sites at the Cu||TiO interface, with photoenhanced degradation courtesy of semiconducting TiO and the surface plasmon resonance (SPR) of the Cu nanoparticles. The TiO aerogel provides a high surface area for sarin binding (155 m g), while the addition of Cu NPs increases the abundance of hydrolytically active OH sites. Degradation is accelerated on TiO and Cu/TiO aerogels with O. Under broadband illumination, which excites the TiO bandgap and the Cu SPR, sarin degradation accelerates, and the products are more fully mineralized compared to those of the dark reaction. With O and broadband illumination, oxidation products are observed on the Cu/TiO aerogels as the hydrolysis products subsequently oxidize. In contrast, the photodegradation of sarin on TiO is limited by its slow initial hydrolysis, which limits the subsequent photooxidation. Accelerated hydrolysis occurs on Cu/TiO aerogels under visible illumination (>480 nm) that excites the Cu SPR but not the TiO bandgap, confirming that the Cu SPR excitation contributes to the broadband-driven activity. The high hydrolytic activity of the Cu/TiO aerogels combined with the photoactivity upon TiO bandgap excitation and Cu SPR excitation is a potent combination of hydrolysis and oxidation that enables the substantial chemical degradation of organophorphorus compounds.
将高容量吸附剂与催化纳米颗粒（NPs）相结合的多功能复合材料，为有机磷污染物或化学战剂（CWAs）的降解提供了一条很有前景的途径。我们将介孔TiO气凝胶与等离子体Cu纳米颗粒（Cu/TiO）相结合，并表征了在黑暗和光照条件下有机磷化学战剂沙林的降解情况。Cu/TiO气凝胶结合了高的暗降解速率，这得益于Cu||TiO界面处的水解活性位点，以及由半导体TiO和Cu纳米颗粒的表面等离子体共振（SPR）带来的光增强降解。TiO气凝胶为沙林结合提供了高表面积（155 m²/g），而Cu NPs的加入增加了水解活性OH位点的数量。在含有O的情况下，TiO和Cu/TiO气凝胶上的降解加速。在宽带光照下，激发了TiO带隙和Cu SPR，沙林降解加速，与暗反应相比，产物更完全地矿化。在含有O和宽带光照的情况下，随着水解产物随后氧化，在Cu/TiO气凝胶上观察到氧化产物。相比之下，沙林在TiO上的光降解受到其缓慢的初始水解的限制，这限制了随后的光氧化。在激发Cu SPR但不激发TiO带隙的可见光照射（>480 nm）下，Cu/TiO气凝胶上发生加速水解，证实了Cu SPR激发有助于宽带驱动的活性。Cu/TiO气凝胶的高水解活性与TiO带隙激发和Cu SPR激发时的光活性相结合，是水解和氧化的有效组合，能够实现有机磷化合物的大量化学降解。
