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In this study, a novel extraction and safety evaluation method for heavy metals based on different functions of plants was proposed, and an edible plant (pea) was used as the research material to explore the feasibility of the novel method. Pea sprouts were cultured in cadmium (Cd) concentrations of 0, 1.0, 3.0, and 5.0 mg L−1, respectively. The Cd in pea sprouts was continuously extracted with 100 °C distilled water, 60% ethanol, 6% acetic acid, and simulated gastric juice. It was observed that highest amount of Cd (48.65–58.87%) was found in the extraction of roots with 6% acetic acid, followed by 100 °C distilled water (28.68–37.61%). While in stems, most of the Cd (70.73–85.39%) was extracted by 6% acetic acid. The recovery rate of the sequential chemical extraction technique employed in this experiment was between 93 and 106%. Compared with traditional methods, this study has its development potential in two aspects. First, it can determine which steps of sequential extractions of heavy metals in plants are the most harmful to humans. Secondly, corresponding measures can be taken to reduce heavy metals in vegetables used daily, such as soaking edible vegetables in vinegar for a short time. Novelty statement: In this study, a novel extraction and safety evaluation method for heavy metals based on different functions of plants was proposed, and an edible plant (pea) was used as the research material to explore the feasibility of the novel method. Compared with the commonly used extraction methods, the novel method is more reasonable and has greater development potential. [ABSTRACT FROM AUTHOR]

TiO2 nanorod arrays of crystalline Cd, Y-co-doped rutile were synthesized and successfully assembled in perovskite solar cells (PSCs) as the photoanode. In this work, CH3NH3PbI3−xClx was used as the light absorber and spiro-OMeTAD as hole transport material (HTM). The synthesized TiO2 nanorod arrays were investigated by field emission-scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRD) and UV-Vis diffused reflectance. FE-SEM images indicate that the co-doped TiO2 nanorod arrays were slightly sparser and shorter in length than that of un-doped ones. XRD pattern demonstrates that the as-prepared TiO2 nanorod arrays were rutile phase. The UV-Vis spectrum proves that the co-doped samples possess higher light scattering intensity than the un-doped samples, which may contribute to improve the short current density of PSCs. And the band gap of the TiO2 nanorod shows a positive shift when doped with cadmium and ytterbium. Furthermore, a negative shift in the flat-band potential (Vfb) was also observed. Finally, the device based on co-doped TiO2 nanorod arrays has improved open circuit voltage (Voc) and short circuit current density (Jsc). A higher power conversion efficiency (η) of 9.06% was obtained for the co-doped device while 8.12% for the un-doped TiO2 nanorod arrays. This paper opens a door to multi-element co-doped 1-D nanostructured materials for the improving the open circuit voltage and short circuit current density of perovskite solar cells. [ABSTRACT FROM AUTHOR]