由于SOM与重金属离子(HMIs)的络合,土壤有机质(SOM)显着影响使用方波阳极溶出伏安法(SWASV)对Cd2和Pb2的检测精度。从而衰减SWASV信号。本研究探索了一种有效的预处理方法,该方法将低压紫外(LPUV)光解与ZnO/g-C3N4光催化剂相结合,激活光催化剂以产生高度氧化的•OH自由基和O2•-自由基,有效地破坏了这种络合,从而恢复HMI的电活性并实现高保真SWASV信号。精心优化了LPUV-ZnO/g-C3N4光催化体系的参数,包括光解的pH值,光解的持续时间,g-C3N4质量分数,和光催化剂的浓度。此外,对ZnO/g-C3N4光催化剂进行了全面表征,深入研究了ZnO与g-C3N4之间的协同相互作用以及促进SWASV信号恢复的机制。这种协同作用有效地分离了载流子并降低了电荷转移电阻,使来自g-C3N4导带的光生电子(e-)快速转移到ZnO的导带,防止e-和h+的重组,并产生更多的自由基来破坏络合并恢复SWASV信号。最后,使用拟议的预处理方法对实际土壤提取物中的HMI进行分析,证明了Cd2+的94.9%和Pb2+的99.8%的高检测精度,验证了该方法在环境应用中的可行性和有效性。
Soil organic matter (SOM) significantly impacts the detection accuracy of Cd2+ and Pb2+ using square wave anodic stripping voltammetry (
SWASV) due to the complexation of SOM to heavy metal ions (HMIs), thereby attenuating
SWASV signals. This study explored an effective pretreatment method that combined low-pressure ultraviolet (LPUV) photolysis with the ZnO/g-C3N4 photocatalyst, activating the photocatalyst to generate highly oxidative •OH radicals and O2•- radicals, which effectively disrupted this complexation, consequently restoring the electroactivity of HMIs and achieving high-fidelity
SWASV signals. The parameters of the LPUV-ZnO/g-C3N4 photocatalytic system were meticulously optimized, including the pH of photolysis, duration of photolysis, g-C3N4 mass fraction, and concentration of the photocatalyst. Furthermore, the ZnO/g-C3N4 photocatalyst was thoroughly characterized, with an in-depth investigation on the synergistic interaction between ZnO and g-C3N4 and the mechanisms contributing to the restoration of
SWASV signals. This synergistic interaction effectively separated charge carriers and reduced charge transfer resistance, enabling photogenerated electrons (e-) from the conduction band of g-C3N4 to be quickly transferred to the conduction band of ZnO, preventing the recombination of e- and hole (h+) and generating more radicals to disrupt complexation and restore the
SWASV signals. Finally, the analysis of HMIs in real soil extracts using the proposed pretreatment method demonstrated high detection accuracy of 94.9% for Cd2+ and 99.8% for Pb2+, which validated the feasibility and effectiveness of the proposed method in environmental applications.