Prediction Paradigm Of Photogenerated Reactive Oxygen Species Induced By Metal Oxide Nanoparticles

Metal oxide nanoparticles?nMOx?have a broad application from photoelectric materials,biomedicine to environmental treatment because of their unique photochemistry properties.Reactive oxygen species?ROS?are thought to be the critical causes affecting the catalytic,antibacterial and cytotoxic properties of nMOx.nMOx have various crystal structures,wide particle size distributions and new materials are springing up.Establishing the prediction paradigm of photogenerated ROS induced by nMOx with different crystal structures and particle sizes has great importance to evaluate the photocatalytic properties and potential ecological risks of nMOx.Based on density functional theory?DFT?and Brus model,this study developed the quantitative prediction models of band gaps of nMOx and evaluated their prediction ability according to internal and external validation.Based on redox potentials of photogenerated ROS,this study established the prediction paradigm of photogenerated ROS induced by nMOx and studied generation kinds and reaction pathways of photogenerated ROS for 16nMOx under 3¹00 nm.In order to evaluate the accuracy of prediction paradigm,this study used electron paramagnetic resonance?EPR?to detect ROS generation for 9 nMOx in water suspensions under the light condition.The results show that the quantitative prediction models of band gaps of nMOx has well robustness?n=24,RMSE=0.55?and external prediction ability?n=8,RMSE=0.48?.Compared with bulk materials,band gaps increase with the decrease of particle sizes.The band gaps significantly increase when particle sizes are less than 5 nm.The prediction paradigm of photogenerated ROS show that under the light condition??<1240/E_g?,nCu₂O?d>6.25 nm?,nZnO?d>3.95 nm?and nSnO₂ can not generate O₂^·-,and the rest of nMOx can generate O₂^·-via reducing O₂.nCu₂O can not generate·OH via oxidizing OH^-or H₂O,and nZnO?d>3.43 nm?can not generate·OH via oxidizing OH^-,and the rest of nMOx can generate·OH via oxidizing H₂O or OH^-.nCu₂O can not generate ¹O₂ via the oxidizing O₂,and the rest of nMOx can generate the¹O₂ via the oxidizing O₂ or O₂^·-.The EPR results show that under the light condition??:280⁵00 nm?,9 nMOx can all generate·OH.While anatase nTiO₂ and nSnO₂ can not generate ¹O₂,the rutile nTiO₂ and nZnO can generate ¹O₂.Comparing predicted and experimental results,the prediction paradigm accuracy of photogenerated ROS induced by nMOx is about 72%.As stated above,this study developed the prediction paradigm of photogenerated ROS kinds and reaction pathways induced by nMOx with different crystal structures and particle sizes.The results can serve for the environmental risk evaluation and safety design of nMOx.