Search

Defects in perovskite films not only challenge the efficiency and stability improvement of perovskite solar cells (PSCs), but also serve as electronic dopants that impact interface energetics and charge-transfer kinetics. To address this issue, herein, we introduced a natural additive into a perovskite precursor to improve the inorganic CsPbI2Br film quality. Arising from the strong interaction between passivation molecules and undercoordinated Pb2+ in the perovskite, the reduction in defects results in effective n-type de-doping of the inorganic CsPbI2Br perovskite surface, concomitantly forming an n/n− homojunction at the top perovskite/carbon interface for accelerating charge extraction and suppressing carrier nonradiative recombination in a carbon-based PSC. Consequently, a cutting-edge efficiency as high as 15.0% was achieved with reduced hysteresis in addition to significantly improved long-term stability for a 65 days storage period in the air (94.74% efficiency retention rate) and persistent light irradiation for over 230 hours in N2 (∼82% efficiency retention rate). [ABSTRACT FROM AUTHOR]

In this study, Fe1Pt3 nanoparticles are dispersed on MoS2 nanosheets to integrate the fascinating features of noble metal with highly exposed nanosheets. The MoS2 nanosheets supply good support for the uniform dispersion and easily accessibility of Fe1Pt3 nanoalloys, and ultrafine Fe1Pt3 nanoparticles provide a large number of active sites and enhanced catalysis/charge kinetics. The Fe1Pt3-MoS2 catalyst exhibits good hydrogen evolution performances in acidic media with low overpotential of 59 mV at current density of 10 mA cm−2 and robust catalysis kinetics (Tafel slope of 38 mV dec−1), making it high-efficiency HER catalyst with low Pt loading. [ABSTRACT FROM AUTHOR]

The application of metal oxides and sulfides for lithium‐ion batteries (LIBs) is hindered by the limited Li+ diffusion kinetics and inevitable structural damage. Pseudocapacitance for electrochemical lithium storage provides an effective and competitive solution for developing electrode materials with large capacity, high rate capability, and stability. Herein, a composite composed of VS4 nanoplates tightly bound to carbon nanotubes (VS4/CNTs) is developed to demonstrate pseudocapacitance‐assisted lithium storage. The texture of the assembled VS4 nanoplates supplies efficient electrolyte/ion diffusion, as well as exposed surface for pseudocapacitive behavior. The effective coupling between VS4 and CNTs ensures fast electron transfer and high stability. The VS4/CNTs anode exhibits high capacity of 1144 mAh g−1 at 0.1 A g−1, superior cycling stability (capacity retention of 100 % at 1 A g−1 after 400 cycles), and good rate capability. The pseudocapacitive behavior plays an important role in determining the excellent electrochemical properties, contributing to the increased charge rate and reaching as high as 42 % of the total charge at a scan rate of 1 mV s−1. This study demonstrates the potential application of metal sulfides with pseudocapacitive contribution in LIBs. [ABSTRACT FROM AUTHOR]

Solidifying the soft lattice of all‐inorganic mixed‐halide perovskites is of great importance to restrain the notorious halide segregation under persistent light illumination. Herein, a multifunctional columnar macrocyclic molecule additive, namely cucurbituril into perovskite precursor to enhance the crystallization and reduce the defect density in the final perovskite film is introduced. Based on the theoretical calculation and simulation, the cucurbituril molecule with a strong double‐ended negatively‐charged cavity surrounded by terminated oxygen atoms not only coordinates with dangling Pb2+ ions to form host‐guest complexation but also induces an electric dipole field at perovskite grain boundary to effectively repel the iodide ion migration from the inside grain to the defective boundary, significantly suppressing the halide segregation and improving the device performance. As a result, the carbon‐based, all‐inorganic CsPbI2Br solar cell achieves an enhanced efficiency of 15.59% with great tolerance to environmental stresses. These findings provide new insights into the development of a novel passivation strategy with macrocyclic molecules for making high‐efficiency and stable perovskite solar cells. [ABSTRACT FROM AUTHOR]

An electrochemical sensor for paracetamol is described that consists of a glassy carbon electrode (GCE) that was modified with the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with MnO2 nanoflowers. The hydrothermally synthesized MnO2 nanoflowers possess a large surface area and can be doped into PEDOT through electrochemical deposition to form a conducting polymer nanocomposite. The nanoflowers are shown to be uniformly distributed within the nanocomposite as revealed by elemental mapping analysis. The nanocomposite displays excellent catalytic activity toward the electrochemical oxidation of paracetamol. The modified GCE, best operated at a working potential of around 0.37 V (vs. SCE) has a linear response in 0.06 to 435 μM paracetamol concentration range and a very low limit of detection (31 nM at a signal-to-noise ratio of 3). The sensor exhibits excellent reproducibility and stability, and satisfying accuracy for paracetamol detection in pharmaceutical samples. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mesoporous Co3O4 octahedra have been prepared with simple sol-gel method. [•] Porous structure buffers the volume change and shortens the diffusion path of Li+. [•] Anisotropy octahedral morphology guarantees structural stability. [•] It exhibits high capacity, superior capacity retention and excellent rate capability. [Copyright &y& Elsevier]