This work aimed to fabricate a boron-doped diamond film electrode for detecting trace amounts of lead in drinking water so as to safeguard it for the public. Available detectors suffer from high costs and complex analytical processes, and commonly used electrodes for electrochemical detectors are subject to a short life, poor stability, and secondary pollution during usage. In this work, a boron-doped diamond (BDD) electrode was prepared on a porous titanium substrate, and the microstructure and electrochemical properties of the BDD electrode were systematically studied. Moreover, the stripping parameters were optimized to obtain a better signal response and determine the detection index. As a result, diamond particles were closely arranged on the surface of the BDD electrode with good phase quality. The electrode showed high electrochemical activity, specific surface area, and low charge transfer resistance, which can accelerate the stripping reaction process of Pb2+. The BDD electrode presented a low detection limit of 2.62 ppb for Pb2+ under an optimized parameter set with an enrichment time of 150 s and a scanning frequency of 50 Hz. The BDD electrode also has good anti-interference ability. The designed BDD electrode is expected to offer a reliable solution for the dilemma of the availability of metal electrodes and exhibits a good application prospect in the trace monitoring of Pb2+ content in drinking water.

Graphene films made by chemical vapor deposition (CVD) are a popular method to modify sensors by virtue of large-scale and reproducibility, but suffer from various surface contamination and structural defects induced during transfer procedures. In-situ growth of graphene films is proposed in this review article to improve sensing performance. Root causes of the surface contamination and structural defects are revealed with several common transfer methods. In-situ approaches are introduced and compared, growing graphene films with clean surfaces and few defects. This allows graphene film to display superior sensing performance for sensor applications. This work may reasonably be expected to offer a good avenue for synthesis of graphene films applicable for sensing applications.

Multi-junction solar cell is of great significance for increasing energy utilization, reducing environmental pollution and improving social and economic benefits. This paper will focus on the methods to improve the conversion efficiency of multiple solar cells based on information retrieval and literature analysis. Specifically, some of the significance milestones of the state-of-art scenarios will be briefly introduced in the field of multi-junction solar cells primarily. Afterwards, two well-performances state-of-art scenarios will be listed and discussed. The most popular methods to improve the conversion efficiency of multi-cell solar cells are compared and analyzed. Besides, some of the current limitations of multi-cell solar cells are demonstrated and a certain prospect for its future development is proposed. These results shed light on better converting solar energy into electric energy needed by human beings.