Zhen Qin,Hang Sun,Yanan Tang,Zhiyong Chang,Shengyan Yin,Zhenning Liu
Inspired by the characteristics that plant leaves are beneficial for solar light absorption, we have prepared a bio-inspired hierarchical assembly of carbonized spinach leaves@Au/ZnO (CS@Au/ZnO) for solar energy utilization. CS@Au/ZnO shows a low light reflectance of 5% and a high specific surface area of 311.41 m 2 /g. CS@Au/ZnO demonstrates higher photocatalytic degradation efficiency: more than 97% of Rhodamine B (RhB) and 61% of ciprofloxacin (CIP) could be degraded in 180 min under the visible light irradiation. In addition, we also tested the photocatalytic H 2 production performance of CS@Au/ZnO and the H 2 evolution rate is 2.384 mmol g −1 h −1 under simulated solar light. CS@Au/ZnO shows a high cycling stability in recyclable photocatalytic degradation and photocatalytic water splitting. Moreover, CS@Au/ZnO shows a swift and steady photocurrent of about 63.6 μA/cm 2 , illustrating a high sensitivity to solar light. The enhanced photocatalysis performance of CS@Au/ZnO could be ascribed to the naturally optimized macroporous structure of CS with high conductivity, which could enhance the light harvesting and carrier transport, simultaneously. Moreover, modification of AuNPs can broaden the light response range of ZnONRs and reduce the probability of electron-hole recombination. Due to the wide availability of plant leaves, CS@Au/ZnO assembly has broad application prospects in photocatalytic degradation of organic pollutions, photovoltaic devices , and photocatalytic H 2 evolution.
Ruyan Hou,Mengmeng Tong,Wanjun Gao,Lei Wang,Tianxi Yang,Lili He
To investigate the degradation and penetration behaviors of the organophosphate insecticide dimethoate applied on spinach leaves, in situ SERS and LC-MS methods were used to detect dimethoate residue on&in spinach leaves picked on different days after treatment (DAT). The SERS and LC-MS methods determined that the dimethoate degradation rate followed first-order kinetics, with a half-life of 3.56 or 4.13 days, depending on the respective method. The correlation coefficient of quantification value of these two methods was 0.9562. With the SERS method, we detected most of the penetrated dimethoate in the depth of 60–110 μm. With the LC-MS method, we detected dimethoate up to 0.17 ng in leaves and that the dimethoate on:in ratio of spinach leaves ranged from 562.25 on 0 DAT to 5.23 on 14 DAT. The combination of these two methods facilitated a better understanding of the behavior and biological fate of pesticides in a complex biological system.