Microstructure characterization of multifunctional As4S4/Fe3O4 nanocomposites prepared by high-energy mechanical milling

Multifunctional As4S4/Fe3O4 nanocomposites prepared by high-energy mechanical milling are probed by complementary methods of positron annihilation lifetime (PAL) spectroscopy, supported by microstructure characterization using X-ray powder diffraction (XRPD) with analysis applied to the first sharp diffraction peak (FSDP), morphology studies by transmission electron microscopy (TEM) with energy-dispersive spectroscopy (EDS) and high-resolution TEM (HRTEM).  These nanocomposites…

Cellulose-polyhydroxylated fatty acid ester-based bioplastics with tuning properties: Acylation via a mixed anhydride system

The synthesis of microcrystalline cellulose (MCC) and 9,10,16-hydroxyhexadecanoic (aleuritic) acid ester-based bioplastics was investigated through acylation in a mixed anhydride (trifluoroacetic acid (TFA)/trifluoroacetic acid anhydride (TFAA)), chloroform co-solvent system. The effects of chemical interactions and the molar ratio of aleuritic acid to the anhydroglucose unit (AGU) of cellulose were investigated. The degree of substitution (DS)…

Synthesis and characterization of Rh/MnO2-CeO2/Al2O3 catalysts for CO-PrOx reaction

Rh/MnO2-CeO2/Al2O3 catalysts with different manganese-to-ceria ratios have been synthesized, characterized and tested in CO-PrOx reaction. The physicochemical properties of the solids were studied by XRD, Raman spectroscopy, BET surface area, H-2-TPR, TGA-DTG and TEM. The differences observed in the textural, structural and redox properties were related to the Mn-to-ceria ratio of the samples. The segregation…

Towards Extending Solar Cell Lifetimes: Addition of a Fluorous Cation to Triple Cation-Based Perovskite Films

Organohalide perovskites have emerged as highly promising replacements for thin-film solar cells. However, their poor stability under ambient conditions remains problematic, hindering commercial exploitation. The addition of a fluorous-functionalized imidazolium cation during the preparation of a highly stable cesium-based mixed perovskite material Cs-0.05(MA(0.15)FA(0.85))(0.95)Pb(I0.85Br0.15)(3) (MA= methylammonium; FA= formamidinium) has been shown to influence its stability. The…

Facile Synthesis of Hybrid Organic–Inorganic Perovskite Microcubes of Optical Quality Using Polar Antisolvents

Herein, we demonstrate a synthetic approach producing highly crystalline methylammonium lead bromide perovskite (MAPbBr3) microcubes at room temperature by injecting a perovskite precursor solution into an environmentally friendly antisolvent (isopropyl alcohol). Confirmed by X-ray and electron diffraction, as well as electron microscopy, these MAPbBr3 microcubes are single crystals and have perfect cubic structure, with sizes varying…

Materials chemistry approaches to the control of the optical features of perovskite solar cells

Perovskite solar cells have revolutionized the field of photovoltaics. Apart from their impressive photo-conversion efficiencies, the ease of their fabrication – principally when carried out by solution processing – has permitted addition of new functionalities to the photovoltaic cell. Some of these features are related to the optical properties. In this review, the different materials…