Advances in Research of Collection and Detection Methods of Microplastics in Environment

As a new type of environmental pollutants,microplastics have gradually attracted people s attention.A large number of plastics discharged into the environment by human beings are constantly aging and breaking,and finally become microplastics.Microplastics can adsorb pollutants in the environment,and their components have certain toxicity,which can cause different degrees of harm to organisms.Due to the structural characteristics of microplastic particles,such as small particle size,large specific surface area,and their distribution in different environmental media,it is very difficult to accurately detect microplastics.Reliable collection and detection methods are the key to the study of environmental behavior of microplastics.In this study,the collection and detection methods of microplastics in the environment were reviewed,and the development direction of microplastics detection technology in the future was prospected.This study has a certain reference value for the related research and the prevention and treatment of micro-plastic pollution.

无人机路径规划在电力巡检中的应用研究

电力行业一直在寻求提高电力系统的可靠性、安全性和效率,以满足不断增长的电力需求。无人机技术的迅猛发展为电力巡检带来了革命性的变革。本文将深入研究无人机路径规划在电力巡检中的应用,包括路径规划方法、关键技术、案例研究以及未来发展趋势。通过对无人机技术的探讨,本文旨在揭示其如何提高电力巡检的效率、减少成本,并提升电力系统的可靠性。

Improved water oxidation via Fe doping of CuWO4 photoanodes:Influence of the Fe source and concentration

Iron(Fe)was successfully doped in CuWO4 photoanode films with a combined liquid-phase spin-coating method via the dopant sources of Fe(NO3)3,FeSO4 and FeCl3.The microstructure of the prepared films was characterized by x-ray diffraction,scanning electron microscopy,and atomic force microscopy.The light absorption and photoelectric conversion properties were evaluated by the UV-visible absorption spectra and monochromatic incident photon-to-electron conversion efficiency.The chemical composition and element combination of the samples were examined by x-ray photoelectron spectroscopy.A linear sweep voltammetric and stability test(I-t)were performed with an electrochemical workstation.The results show that the samples are uniform with a thickness of approximately 800 nm and that the photoelectrochemical performance of the doped films is heavily dependent on the Fe source and dopant concentration.Upon optimizing the doping conditions of Fe(NO3)3 and the optimal source,the photocurrent density in the Fe-doped CuWO4 photoanode film is improved by 78%from 0.267 mA/cm2 to 0.476 mA/cm2 at 1.23 V vs reversible hydrogen electrode.The underlying causes are discussed.

Random lasing of CsPbBr3 perovskite thin films pumped by modulated electron beam

Aiming at the application requirements of information optics,this Letter proposed a perovskite quantum dot random lasing pumping method suitable for high-speed modulation.At the same time,the luminescence characteristics of perovskite quantum dot films under electron beam pumping conditions are analyzed,and the random lasing mechanism of electron beam pumping CsPbBr3 quantum dot films is revealed.Finally,it is confirmed that perovskite quantum dots are easy to realize random lasing under electron beam pumping conditions.

120 mm Single-crystalline perovskite and wafers： towards viable applications

As the large single-crystalline silicon wafers have revolutionized many industries including electronics and solar cells, it is envisioned that the availability of large single-crystalline perovskite crystals and wafers will revolutionize its broad applications in photovoltaics, optoelectronics, lasers, photodetectors, light emitting diodes(LEDs), etc. Here we report a method to grow large single-crystalline perovskites including single-halide crystals: CH3NH3PbX3(X=I, Br, Cl), and dual-halide ones:CH3NH3Pb(ClxBr1.x)3 and CH3NH3Pb(BrxI1.x)3, with the largest crystal being 120 mm in length. Meanwhile, we have advanced a process to slice the large perovskite crystals into thin wafers. It is found that the wafers exhibit remarkable features:(1)its trap-state density is a million times smaller than that in the microcrystalline perovskite thin films(MPTF);(2) its carrier mobility is 410 times higher than its most popular organic counterpart P3HT;(3) its optical absorption is expanded to as high as910 nm comparing to 797 nm for the MPTF;(4) while MPTF decomposes at 150 °C, the wafer is stable at high temperature up to270 °C;(5) when exposed to high humidity(75% RH), MPTF decomposes in 5 h while the wafer shows no change for overnight;(6) its photocurrent response is 250 times higher than its MPTF counterpart. A few electronic devices have been fabricated using the crystalline wafers. Among them, the Hall test gives low carrier concentration with high mobility. The trap-state density is measured much lower than common semiconductors. Moreover, the large SC-wafer is found particularly useful for mass production of integrated circuits. By adjusting the halide composition, both the optical absorption and the light emission can be fine-tuned across the entire visible spectrum from 400 nm to 800 nm. It is envisioned that a range of visible lasers and LEDs may be developed using the dual-halide perovskites. With fewer trap states, high mobility, broader absorption, and humidity resistance, it is expected that solar cells with high stable efficiency maybe attainable using the crystalline wafers.

Embedding laser generated GaAs nanocrystals in perovskite wires for enhanced charge transport and photodetection

Solution-processed perovskite wires are attractive candidates for photodetectors(PDs)due to their simple processibility as well as one-dimensional(1D)geometry with desirable charge carrier transport.However,the performance of the perovskite PDs is generally restricted by the charge carrier transport and extraction efficiency.Herein,we demonstrate that the charge transport and the consequent photodetection performance of MAPbI_(3)perovskite wires can be effectively enhanced by incorporating nanocrystals(NCs)of GaAs-a semiconductor with high charge carrier mobility.Taking advantage of the pulsed laser irradiation technique,we successfully fabricate ligand-free GaAs NCs with a size of~7 nm and homogeneously embed them in MAPbI_(3) perovskite wires through a simple solution-processed synthesis route.Compared with the pristine perovskite wires,the GaAs NCs modulated perovskite wires show improved charge carrier transport with the mobility rising from 1.13 to 3.67 cm^(2)V^(-1)s^(-1),and the resultant PD shows significant improvement in responsivity and detectivity.This study provides a new strategy for improving optoelectronic properties of halide perovskite materials and optimizing the device performance.