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• A novel Cu 2.3 Al 1.3 Ni 1.7 SnCr 0.3 multi-principal element alloy (MPEA) and a multi-step ultrasonic assisted (UA) laser remelting technology were proposed. • An unusual ultrafine lamellar eutectic structure exists in Cu 2.3 Al 1.3 Ni 1.7 SnCr 0.3 UA-MPEA coating. • The effect of the FCC and eutectic phases on the corrosion behavior of the Cu 2.3 Al 1.3 Ni 1.7 SnCr 0.3 MPEA coatings was studied. • The passive films formed on the Cu 2.3 Al 1.3 Ni 1.7 SnCr 0.3 MPEA coatings exhibits duplex semiconductor behavior in NaCl solution. The evaporation and dilution of substrate seriously limit the performance of laser cladding coatings on magnesium alloys. In order to overcome the above shortcomings, a multi-step ultrasonic assisted laser remelting technology was proposed to improve the performance of the coating. In this work, a novel Cu 2.3 Al 1.3 Ni 1.7 SnCr 0.3 multi-principal element alloy coating (MPEAC) was prepared on the surface of magnesium alloy. Characterization techniques such as transmission electron microscopy (TEM), electron back scatter diffraction (EBSD) and scanning electron microscopy (SEM) were employed to characterize the microstructure and phase composition of the coatings. And the phase structure and morphology at the interface between the coating and the substrate were also studied via focus ion beam (FIB) and TEM method. In addition, the corrosion and wear resistance ability of the coatings were monitored by potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS), hardness and friction tests. The results show that Cu 2.3 Al 1.3 Ni 1.7 SnCr 0.3 MPEAC with ultrasonic assisted is composed of FCC phase and eutectic phases (Cu 10 Sn 3 and Cu 2 Ni 3 Sn 3). Due to the forced convection generated by ultrasonic waves, some Cu and Ni phases are precipitated around Cu 2 Ni 3 Sn 3 phases, which is beneficial to enhance the corrosion resistance. Because of the grain refinement effect caused by ultrasonic, the wear resistance of the coating is also improved. Furthermore, ultrasonic vibration can effectively weaken and eliminate the texture density of the Cu 2.3 Al 1.3 Ni 1.7 SnCr 0.3 MPEAC fabricated by laser cladding. [ABSTRACT FROM AUTHOR]

As a “sister” of porphyrins, boron dipyrromethenes (BODIPY) have attracted widespread attention because of their strong absorption in the visible region. Although many modifications have been made to its structure, the photoelectric conversion efficiency (PCE) below 10% limits its practical application in dye-sensitized solar cells (DSSCs). In this work, heterocycles were introduced into the BODIPY π-bridge to improve the photoelectric properties of dyes. Theoretical calculations show that the introduction of heterocycles, such as cyclopentadiene, pyrrole, furan, and thiophene, not only increases the molecular planarity and narrows the band gap but also enhances the light harvesting ability. Based on these exciting results, the dye/(TiO2)38adsorption models and parameters related to DSSC performance including short-circuit current, open circuit voltage, and PCE were considered to evaluate the overall properties of the investigated dyes. These dyes achieve a PCE value of at least 15.25%, wherein the PCE value of dye inserted thiophene into BODIPY can be as high as 23.12%, which are expected to have potential application in DSSC devices.

Dye-sensitized solar cells based on boron dipyrromethene (BODIPY) have gained widespread attention in recent years because of their easy structural modification, strong light absorption, and photostability. In this paper, a series of dyes with single or double acceptors based on the BODIPY framework have been designed and compared by density functional theory calculation. Results show that the dyes with double acceptors exhibit smaller band gap and broader red-shift absorption peaks than their counterparts with single acceptors. To further improve the dye performance, polythiophenes and electron donating groups are successively introduced into BODIPY and donor moieties of double-acceptor dyes. The introduction of polythiophene effectively improved the light harvesting efficiency (LHE) from 0.79 to 0.96. And, the stronger electron donating groups create a narrow band gap, resulting in a broad absorption band in the range of 400–1600 nm. These modifications not only broaden the absorption range but also facilitate electron injection, thereby improving the photoelectric conversion efficiency, which is beneficial for the potential application of BODIPY sensitizers in the field of photovoltaics.

Formamidinyl tin iodide (FASnI3, FA+= NH2CHNH2+) has attracted enormous attention due to the higher thermal stability, less pollution, and excellent photoelectric properties. However, oxidation of tin may result in tin vacancy defects, which not only reduce the photoelectric conversion efficiency (PCE) but also limit its practical application in perovskite solar cell materials. In this paper, to restrain the oxidability and improve the PCE of the structure, Mg/Ge/Si and Br double-doped to FASnI3were studied by density functional theory (DFT). The results about geometric and photoelectric properties show that appropriate doping can increase the stability, tune the band gap, and improve the charge transfer balance. Among all the discussed doping ratios, FASn0.75Mg0.25I2Br and FASn0.75Mg0.25IBr2are expected to be used as candidates for the light-absorbing layer of perovskite solar cells because of their high stability and excellent properties.

The effect of rare earths (La, Ce and Pr) addition on residual stress in iron coatings prepared by brush plating was investigated. The results showed that the addition of rare earth transformed the residual stress in the coating from tensile to compressive. To relieve the residual stress, on the one hand, RE elements segregated at the grain boundaries which restricted the coalescence of the grains and provided more capability of grain deformation. On the other hand, RE elements could purify detrimental element and absorb hydrogen atoms in the coating. Among the three rare earths, elements lanthanum showed the most significant effect on surface morphology and residual stress.

A chemiluminescence (CL) method using flow injection (FI) was developed for the determination of uric acid based on the enhancement chemiluminescence intensity of luminol–hexacyanoferrate(III)–hexacyanoferrate(II) in the presence of cetyltrimethylammonium bromide and the uric acid species. The linear range was 7.0 × 10–10–9.0 × 10–7M with a detection limit (3σ) of 2.58 × 10–10M, which was about two orders of magnitude lower than those reported. The proposed method was used for the determination of uric acid in real samples.