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Herein, we report the preparation of nanocomposites using activated biochar derived from rice husk (RHBC) by doping with a metal–organic framework, namely the zeolitic imidazolate framework (ZIF-8). The morphological and structural characterization of the prepared nanocomposite was performed using SEM, BET, XRD, FTIR, TGA, and UV–Vis spectroscopy. The average particle sizes as observed from SEM micrographs for ZIF-8 and ZIF-8@RHBC were 67 nm and 78 nm, respectively. The BET surface analysis of the ZIF-8@RHBC composite showed a value of 308 m2/g and a pore diameter of about 42.56 A°. The inclusion of RHBC in ZIF-8 resulted in a 4% increase in the optical band gap and a 5% increase in the optical conductivity. The electrochemical properties of this nanocomposite were investigated through cyclic voltammetry, and it was observed that ZIF-8@RHBC showed improved CV curves in comparison to bare ZIF-8. The specific capacitance of ZIF-8@RHBC was significantly enhanced from 348 F/g to 452 F/g at a 1 A/g current density after incorporating ZIF-8 into the RHBC matrix. The formation of a mesoporous structure in the ZIF-8@RHBC composite contributed to the improved diffusion rate at the electrode surface, resulting in excellent electrochemical features in the composite. Furthermore, the EIS studies confirmed the reduced charge transfer resistance and increased conduction at the electrode surface in the case of the ZIF-8@RHBC composite. Owing to the ease of its green synthesis and its excellent structural and morphological features and optical and electrochemical properties, this ZIF@RHBC nanocomposite could represent a novel multifunctional material to be used in optoelectronics and energy storage applications. [ABSTRACT FROM AUTHOR]

The mitigation influence of N1-(4-(dimethylamino)benzylidene)-N2-(2-((4-(dimethylamino)benzylidene)amino)ethyl)ethane1,2-diamine, (DBDB) against the corrosion of carbon steel and H2 production in 1.0 M HCl solution was studied. The experimental methods of mass loss, gasometry, potentiodynamic polarization, PDP, and electrochemical impedance spectroscopy, EIS, were utilized. The PDP data confirmed that the DBDB compound attitude is a mixed-type inhibitor. The protection efficacy rises with increasing the added amount of DBDB to reach 97% at 0.005 M concentration and 25 °C. The mitigation process was based on the adsorption of the DBDB molecules on the carbon steel obeying Langmuir's model. Some thermodynamic functions like Kads and ΔG°ads are computed and discussed. The negative sign of ΔG°ads proves the stability of the adsorbed DBDB molecules on the corroded metal surface. The ΔG°ads values vary between −38.70 and −35.13 kJ/mol explaining the existence of both the physical- and chemisorption mixed processes. The lowering in the Kads value with temperature confirms that the adsorption of DBDB compound is favorable at lower temperatures. Theoretical quantum calculations agreed with the experimental data. [ABSTRACT FROM AUTHOR]

Traditional methods of synthesizing nanomaterials via physical or chemical methods are typically expensive and result in toxic byproducts that adversely affect the environment. In this study, we propose synthesis, characterization, optical and sensing properties of hybrid nanocomposites consisting of Fe-1,4-benzene-dicarboxylates (Fe-BDC) as a porous metal-organic framework (MOF) doped with 10 wt. % of Biochar (BC) derived from food waste (Fe-BDC@BC). The bio-based MOF was characterized by using SEM, TGA, FTIR, and XRD. The structural investigation showed that BC improved the porosity, thermal stability, and crystallinity of Fe-BDC, resulting in a particle size of around 50 nm. Optical investigation showed that the energy gap of the bio-doped MOF decreased by about 6%. A sensitive layer of Fe-BDC@BCs was created on an ITO substrate using the spin coating method to study humidity sensing. The dynamic response of the FE-BDC@BC nanocomposite sensor to the change in humidity from 10% to 95% RH. Fe-BDC@BC demonstrated a sensitive response to humidity of about 96% and quick reaction and recovery times of 10 s and 50 s, respectively, Due to their ease of synthesis, and excellent optical and humidity-sensing response, these bio-based MOFs could be used for the fabrication of optoelectronic and sensing devices. [ABSTRACT FROM AUTHOR]

Cobalt aluminate/carbon composite nanoparticles have been synthesised by utilising an auto-combustion method using glycine as an inexpensive fuel. The products were analysed by various techniques such as powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermal analysis (TG), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectrum (DRS), energy-dispersive X-ray spectroscopy (EDS). The results exhibited that the average crystallite size of the as-prepared CoAl2O4/C nanocomposite was ca. 26 nm. The photocatalytic activity of the as-prepared catalyst was evaluated through the degradation of methylene blue (MB) dye under different conditions, and the photocatalytic degradation mechanism was proposed. The results indicated that CoAl2O4/C nanocomposite has a high catalytic performance for the photocatalytic degradation of MB dye under UV illumination in the presence of H2O2. The degradation efficiency reached 98.5% in 90 min with a degradation rate constant of 0.046 min−1. [ABSTRACT FROM AUTHOR]

The wide-ranging potential of polyaniline (PANI) composites in energy storage, electrochemical, sensing, and electromagnetic shielding applications emphasizes researchers to improve its properties. Here, the doping of ZnFe2O4 nRs by 1, 3, and 5 wt. % within polyaniline has been done. Then, we characterize the doped material using techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR) to verify the successful incorporation of polyaniline onto the nRs. TGA showed that doping of PANI with ZnFe2O4 nRs enhanced the interfacial interactions between the two components. This provided a more stable matrix structure and enhanced the thermal stability of the composite. The transmission of light has been increased by about 18% due to the increase in crystallinity accompanied by ZnFe2O4 doping. As the ZnFe2O4 nRs doping rose, our PANI samples' optical band gap values slightly decreased by about 10%. In addition, it has been found that the optical characteristics such as refractive index, extension coefficient, surface, and volume energy loss function essentially showed ZnFe2O4 doping dependency. The nonlinear constants of the doped samples have increased due to the new charge carriers and altered the electronic and optical properties of the composite material. Our obtained results show that PANI@ ZnFe2O4 nRs have potential applications such as optical sensors, electrochemical, optoelectronics, and photocatalysis. [ABSTRACT FROM AUTHOR]