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The primary objective of this research is to address the energy challenges by introducing an innovative nanocomposite material. This material is designed to facilitate the conversion of environmentally friendly and economically viable Red Sea water into hydrogen gas. The ultimate goal of this work is to pave the way for the development of a practical device that can be employed within households and industrial settings to directly convert water into hydrogen gas. This novel nanocomposite material synthesized through oxidative polymerization comprises As2O3 and Poly-3-methylaniline (P3MA). This material possesses an extensive absorption range, spanning up to 700 nm, and features a bandgap of 1.75 eV, making it a promising candidate for use as a photoelectrode in green hydrogen production. The unique aspect of this setup lies in the utilization of Red Sea water, a natural sacrificing agent, as the electrolyte, rendering the process eco-friendly and cost-effective. When it is employed as a photoelectrode, this material exhibits high sensitivity to green hydrogen production, generating 6 moles/10 cm2·h of hydrogen. At a voltage of −0.83 V, the current density values are measured as −0.08 mA·cm−2 (Jph) in light and −0.02 mA·cm−2 (Jo) in darkness. Furthermore, the photoelectrode’s responsiveness to light is assessed with different optical filters, revealing the optimal performance at 340 nm, where Jph reaches −0.052 mA·cm−2. These outcomes provide strong evidence of the photoactivity of the As2O3/P3MAphotoelectrode for green hydrogen production using Red Sea water. This underscores its potential for the development of an electrochemical cell for the direct conversion of sea water into H2 gas.

In this study, O-amino benzenethiol (OABT) was oxidized in one pot using Fe(NO3)3 to produce a novel Fe2S3-Fe2O3/poly O-amino benzenethiol (POABT), which showed a highly uniform morphology. At the same time, from SEM analysis, highly wrinkled porous polypyrrole (Ppy) and porous ball-like POABT structures prepared from the K2S2O8 route were evidenced by SEM and TEM analyses. A nanocomposite pseudo-supercapacitor (SC) was fabricated using Fe2S3-Fe2O3/POABT, and its performance was tested with and without incorporating Ppy in the paste. The results indicate that Ppy significantly increased the specific capacitance (CS) values, indicating an enhancement in charge storage. At a current density of 0.2 A/g, the CS values were 44 F/g and 161 F/g for the paste without and with Ppy, respectively. Additionally, the E was calculated, and the incorporation of Ppy resulted in a significant increase in E, reaching 30 W.h.kg−1; this was significantly higher than the value of 8.18 W.h.kg−1 observed without Ppy materials. This effect is likely due to the improved charge transfer facilitated by the presence of Ppy, as evidenced by the Nyquist plot, where the Rct values were 1.1 Ω and 2.1 Ω with and without Ppy, respectively. Overall, the low cost and significant technical advantages of this capacitor make it a promising candidate for commercial applications.

Because of the expensive nature of sensors used to detect heavy metals and the severe health risks associated with certain heavy metals, there is a pressing need to develop cost-effective materials that are highly efficient in detecting these metals. A flower-shaped WO2I2-Poly(1H-pyrrole) (WO2I2/P1HP) nanocomposite thin film is synthesized through the oxidation of 1-H pyrrole using iodine and subsequent reaction with Na2WO4. The nanocomposite exhibits a distinctive flower-like morphology with an average size of 20 nm. Elemental composition and chemical structure are confirmed via X-ray photoelectron spectroscopy (XPS) analyses, while X-Ray diffraction analysis (XRD) and Fourier-transform infrared spectroscopy (FTIR) analyses provide further evidence of crystalline peaks and functional groups within the composite. The potential of the nanocomposite as a sensor for Cd2+ ions is determined using two approaches: simple potentiometric (two-electrode cell) and cyclic voltammetric (three-electrode cell) methods, over a concentration range spanning from 10−6 to 10−1 M. From the simple potentiometric method, the sensor showcases strong sensing capabilities in the concentration span of 10−4 to 10−1 M, displaying a Nernstian slope of 29.7 mV/decade. With a detection limit of 5 × 10−5 M, the sensor proves adept at precise and sensitive detection of low Cd2+ ion concentrations. While using the cyclic voltammetric method, the sensor’s selectivity for Cd2+ ions, demonstrated through cyclic voltammetry, reveals a sensitivity of 1.0 × 10−5 A/M and the ability to distinguish Cd2+ ions from other ions like Zn2+, Ni2+, Ca2+, K+, Al3+, and Mg2+. This selectivity underscores its utility in complex sample matrices and diverse environments. Furthermore, the sensor’s successful detection of Cd2+ ions from real samples solidifies its practical viability. Its reliable performance in real-world scenarios positions it as a valuable tool for Cd2+ ion detection across industries and environmental monitoring applications. These findings advocate for its utilization in commercial settings, highlighting its significance in Cd2+ ion detection.

A quantum dot (QD) thin film of arsenic (III) oxide-hydroxide/polypyrrole (As2S3-As2O3/Ppy) with a supernova-like shape has been developed for optoelectronic applications across a wide optical range, spanning from ultraviolet (UV) to infrared (IR). The fabrication process involves the polymerization of pyrrole to form Ppy in the presence of NaAsO2 and K2S2O8. The resulting QD exhibits a remarkable morphology characterized by a supernova-like structure and a porous nature with a particle size of 4 nm. The unique morphology of the QD contributes to its optical properties. The material demonstrates a maximum optical absorbance that extends up to 600 nm. The chemical structure of the composite has been proved using various characterization techniques. The As2S3-As2O3/Ppy QD thin film holds significant potential for optoelectronic applications, particularly in light detection across multiple optical regions. Its sensitivity has been evaluated through the measurement of photoresponsivity (R), yielding a high value of 0.31 mA/W. This indicates a substantial current density (Jph) of 0.031 mA/cm2 at a wavelength of 340 nm. Additionally, the detectivity (D) of the photodetector has been calculated based on these values, resulting in a detection capability of 6.9 × 107 Jones. This indicates the ability to detect low levels of photons using this photodetector. The highly reproducible nature of this photodetector enables its application in various optoelectronic systems. The As2S3-As2O3/Ppy QD thin film offers great promise as a versatile optoelectronic application with its wide optical range, excellent sensitivity, and detectivity.

A highly uniform spherical MoO2-MoO3/polypyrrole core-shell nanocomposite has been successfully synthesized as an optoelectronic photon sensing material, capable of detecting light in the UV, Vis, and IR domains. The nanocomposite is prepared through the oxidation of pyrrole using Na2MoO4, resulting in a uniform spherical morphology that has been confirmed by TEM, theoretical modeling, and SEM analyses. This morphology contributes to its promising optical behavior, characterized by a small bandgap of 1.36 eV. The optoelectronic photosensing capability of the nanocomposite has been evaluated across the UV, Vis, and IR spectra, demonstrating high efficiency. The photoresponsivity R values indicate the ability of the nanocomposite to generate hot electrons in response to incident photons. With an R value of 4.15 mA·W−1 at 440 nm, this optoelectronic device exhibits considerable promise for integration into an advanced technological apparatus. The detection (D) value of 9.30 × 108 Jones at 440 nm further confirms the high sensitivity in the Vis region. The excellent stability of the device can be attributed to the inherent MoO2-MoO3 oxide and Ppy polymer materials. This stability has been demonstrated through reproducibility studies and current-voltage measurements under various optical conditions. The combination of stability, efficiency, and sensitivity makes this optoelectronic device well suited for light sensing applications in both industrial and commercial settings. Its promising performance opens up opportunities for advancements in various fields requiring accurate and reliable light detection.

This study highlights the utilization of the Cr2S3-Cr2O3/P2ABT nanocomposite photoelectrode for efficient and highly sensitive photon absorption, enabling the generation of green hydrogen through the production of hot electrons upon illumination. The nanocomposite is synthesized via a one-pot reaction using K2Cr2O7 and 2-aminobenzene-1-thiol monomer, and the presence of Cr2S3-Cr2O3 is confirmed by XRD and XPS analysis within the composite. The optical properties of the Cr2S3-Cr2O3/poly-2-aminobenzene-1-thiol composite exhibit wide spectral coverage from UV to IR, with a bandgap of 1.6 eV. The diverse morphological behavior observed in the composite correlates with its optical properties, with the cleft spherical particles of the pure polymer transforming into rod-like structures embedded within the polymer matrix. The generated hydrogen gas demonstrates an impressive efficiency of 40.5 mole/10.cm2.h through electrochemical testing. The current density (Jph) values are evaluated under different light frequencies using optical filters ranging from 730 to 340 nm, resulting in Jph values of 0.012 and 0.014 mA.cm−2, respectively. These findings present a promising avenue as green hydrogen for industrial applications, leveraging the potential of the Cr2S3-Cr2O3/P2ABT nanocomposite photoelectrode.

This study achieved the decoration of poly-3-methyl aniline (P3MA) with As2O3–As(OH)3 using K2S2O8 and NaAsO2 on the 3-methyl aniline monomer. This resulted in a highly porous nanocomposite polymer composite with wide absorption optical behavior, an average crystalline size of 22 nm, and a 1.73 eV bandgap. The photoelectrode exhibited a great electrical response for electroanalytical applications, such as photon sensing and photodiodes, with a Jph of 0.015 mA/cm2 and Jo of 0.004 mA/cm2. The variable Jph values ranged from 0.015 to 0.010 mA/cm2 under various monochromatic filters from 340 to 730 nm, which demonstrates high sensitivity to wavelengths. Effective photon numbers were calculated to be 8.0 × 1021 and 5.6 × 1021 photons/s for these wavelength values, and the photoresponsivity (R) values were 0.16 and 0.10 mA/W, respectively. These high sensitivities make the nanocomposite material a promising candidate for use in photodetectors and photodiodes, with potential for commercial applications in highly technological systems and devices. Additionally, the material opens up possibilities for the development of photodiodes using n- and p-type materials.

Abstract The unique optical properties of metal nitrides enhance many photoelectrical applications. In this work, a novel photodetector based on TiO2/TiN nanotubes was deposited on a porous aluminum oxide template (PAOT) for light power intensity and wavelength detection. The PAOT was fabricated by the Ni-imprinting technique through a two-step anodization method. The TiO2/TiN layers were deposited by using atomic layer deposition and magnetron sputtering, respectively. The PAOT and PAOT/TiO2/TiN were characterized by several techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive X-ray (EDX). The PAOT has high-ordered hexagonal nanopores with dimensions ~ 320 nm pore diameter and ~ 61 nm interpore distance. The bandgap of PAOT/TiO2 decreased from 3.1 to 2.2 eV with enhancing absorption of visible light after deposition of TiN on the PAOT/TiO2. The PAOT/TiO2/TiN as photodetector has a responsivity (R) and detectivity (D) of 450 mAW-1 and 8.0 × 1012 Jones, respectively. Moreover, the external quantum efficiency (EQE) was 9.64% at 62.5 mW.cm−2 and 400 nm. Hence, the fabricated photodetector (PD) has a very high photoelectrical response due to hot electrons from the TiN layer, which makes it very hopeful as a broadband photodetector.

A uniform and highly porous reduced graphene oxide/poly-2-aminobenzene-1-thiol multi-layer (R-GO/P2ABT-ML) nanocomposite was synthesized and characterized. The uniform layer structure and porosity of the nanocomposite, combined with its conductivity, make it an ideal candidate for use as a pseudo supercapacitor. To enhance the capacitance behavior, a porous ball structure polypyrrole (PB-Ppy) was incorporated into the nanocomposite. When tested at 0.2 A/g, the capacitance values of the R-GO/P2ABT-ML and R-GO/P2ABT-ML/PB-Ppy were found to be 19.6 F/g and 92 F/g, respectively, indicating a significant increase in capacitance due to the addition of PB-Ppy. The energy density was also found to increase from 1.18 Wh.kg−1 for R-GO/P2ABT-ML to 5.43 Wh.kg−1 for R-GO/P2ABT-ML/PB-Ppy. The stability of the supercapacitor was found to be significantly enhanced by the addition of PB-Ppy. The retention coefficients at 100 and 500 charge cycles for R-GO/P2ABT-ML/PB-Ppy were 95.6% and 85.0%, respectively, compared to 89% and 71% for R-GO/P2ABT-ML without PB-Ppy. Given the low cost, mass production capability, and easy fabrication process of this pseudo capacitor, it holds great potential for commercial applications. Therefore, a prototype of this supercapacitor can be expected to be synthesized soon.

A Ag2S-Ag2O-Ag/poly-2-aminobenzene-1-thiol (P2ABT) nanocomposite was prepared using the photopolymerization reaction using AgNO3 as an oxidant. The size of the nanocomposite was about 40 nm, in which the morphology was confirmed using TEM and SEM analyses. The functional groups of Ag2S-Ag2O-Ag/P2ABT were confirmed using FTIR; also, XRD confirmed the inorganic Ag2S, Ag, and Ag2O formation. This nanocomposite has great performance in supercapacitor applications, with it tested in acidic (1.0 M HCl) and basic mediums (1.0 M NaOH). This pseudo-capacitor has great performance that appeared through the charge time in an acid medium in comparison to the basic medium with values of 118 s and 103 s, correspondingly. The cyclic voltammetry (CV) analysis further confirmed the excellent performance of the supercapacitor material, as indicated by the large area under the cyclic curve. The specific capacitance (CS) and energy density (E) values (at 0.3 A/g) were 92.5 and 44.4 F/g and 5.0 and 2.52 W·h·Kg−1 in the acidic and basic mediums, correspondingly. The charge transfer was studied through a Nyquist plot, and the produced Rs values were 4.9 and 6.2 Ω, respectively. Building on these findings, our objective is to make a significant contribution to the progress of supercapacitor technology through a prototype design soon.

This research paper aims to fabricate flexible PVA/Cs/TiO2 nanocomposite films consisting of polyvinyl alcohol (PVA), chitosan (Cs), and titanium oxide (TiO2) for application in energy storage devices. The samples were analyzed using X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray (EDX) techniques. The impact of TiO2 on the electrical impedance, conductivity, permittivity, and energy efficiency of the PVA/Cs was determined in a frequency range of 100 Hz to 5 GHz. The XRD, FTIR, and EDX results showed the successful fabrications of the PVA/Cs/TiO2. The SEM and AFM images illustrated that the TiO2 was loaded and distributed homogenously in PVA/Cs chains. In addition, the electrical conductivity was enhanced from 0.04 × 10−7 S.cm−1 of PVA/Cs to 0.25 × 10−7 S.cm−1 and 5.75 × 10−7 S.cm−1, respectively, for the composite PVA/Cs/0.01TiO2 and PVA/Cs/0.1TiO2, and the dielectric constant grew from 2.46 for PVA/Cs to 7.38 and 11.93, respectively. These results revealed that modifications were made to the produced films, paving the way for using the composite PVA/Cs/TiO2 films in different energy applications, such as electronic circuits and supercapacitors.

This study explores the effects of Si and Si-P heteroatoms doping and co-doping on a monolayer graphene surface through density functional analysis. The results suggest that doping with Si and co-doping with Si-P significantly alters the bonding arrangement of the atoms surrounding the graphene sheet. Additionally, the surface of the graphene material had a high concentration of electrons in both Si doping and Si-P co-doping, based on electron population analysis. The HOMO–LUMO gap of graphene sheets was found to decrease in the following order: pristine graphene sheet > Si-doped graphene sheet > Si-P co-doped graphene sheet. Furthermore, a TD-DFT study revealed that the absorption wavelength of Si and Si-P co-doped graphene systems had a greater shift to a lower range compared to pristine graphene. The order of decreasing absorption wavelength is Si-P co-doped graphene, Si doped graphene, and pristine graphene. These materials are suggested to have a high potential for photodetector applications due to their broad absorption range.

A graphene oxide (GO)/poly 3-methyl aniline (P3MA) photodetector has been developed for light detection in a broad optical region: UV, Vis, and IR. The 3-methyl aniline was initially synthesized via radical polymerization using an acid medium, i.e., K2S2O8 oxidant. Consequently, the GO/P3MA composite was obtained through the adsorption of GO into the surface of P3MA. The chemical structure and optical properties of the prepared materials have been illustrated via XRD, FTIR, SEM, and TEM analysis. The absorbance measurements demonstrate good optical properties in the UV, Vis, and near-IR regions, although a decrease in the bandgap from 2.4 to 1.6 eV after the composite formation was located. The current density (Jph) varies between 0.29 and 0.68 mA·cm−2 (at 2.0 V) under dark and light, respectively. The photodetector has been tested using on/off chopped light at a low potential, in which the produced Jph values decrease from 0.14 to 0.04 µA·cm−2, respectively. The GO/P3MA photodetector exhibits excellent R (and D) values of 4 and 2.7 mA·W−1 (0.90 × 109 and 0.60 × 109 Jones) in the UV (340 nm) and IR (730 nm) regions, respectively. The R and D values obtained here make the prepared photodetector a promising candidate for future light detection instruments.

This study describes the synthesis of delafossite, CuFeO2, as a primary photocatalytic material for hydrogen generation. A photoelectrode, CuFeO2/CuO/Cu, was prepared by combusting a Cu foil dipped in FeCl3 in ambient air. This photoelectrode showed excellent optical behavior for the hydrogen generation reaction from sewage water, producing 90 µmol/h of H2. The chemical structure was confirmed through XRD and XPS analyses, and the crystalline rhombohedral shape of CuFeO2 was confirmed using SEM and TEM analyses. With a bandgap of 1.35 ev, the prepared material displayed excellent optical properties. Electrochemical measurements for H2 gas generation were carried out using the CuFeO2/CuO/Cu photoelectrode, comparing the effect of light and dark and monochromatic wavelength light. The electrode exhibited significant enhancement in light compared to dark, with current density (Jph) values of −0.83 and −0.1 mA·cm−2, respectively. The monochromatic light also had a noticeable effect, with the Jph value increasing from −0.45 to −0.79 mA·cm−2 as the wavelength increased from 640 to 390 nm. This system is cheap and durable, making it a promising solution for hydrogen gas fuel generation in the industry.

An eco-friendly green synthesis of mesoporous iron oxide (hematite) using pomegranate peels through a low-cost and massive product method was investigated. The mass of pomegranate peels was varied to control the morphology of the produced hematite (Fe2O3). The structures, textures and optical properties of the products were investigated by FTIR, XRD, FE-SEM, and UV–Vis spectroscopy. Three different Fe2O3 morphologies were obtained; Fe2O3(I) nanorod like shape, Fe2O3(II) nanoparticles, and Fe2O3(III) nanoporous structured layer. The bandgap values for Fe2O3 (I), (II) and (III) were 2.71, 2.95, and 2.29 eV, respectively. The newly hematite samples were used as promising photoelectrodes supported on graphite substrate for the photoelectrochemical (PEC) water splitting toward the efficient production of solar hydrogen. The number of generated hydrogen moles was calculated per active area to be 50 μmol h−1 cm−2 for electrode III, which decreased to 15.3 μmol h−1 cm−2 for electrode II. The effects of temperature (30–70 °C) on the PEC behavior of the three electrodes were addressed. Different thermodynamic parameters were calculated for the three electrodes, which showed activation energies of 13.4, 16.8, and 15.2 kJ mol−1, respectively. The electrode stability was addressed as a function of the number of runs and exposure time in addition to electrochemical impedance study. Finally, the conversion efficiency of the incident photon-to-current (IPCE) was estimated under the monochromatic illumination. The optimum value was ∼11% @ 390 nm for Fe2O3(III) electrode.

This study describes the preparation and characterization of glass/poly-3-methyl aniline (P3MA)/PbS quantum dot (QD) optoelectronic photodetector to detect and sense the light in broad spectral regions of UV, Vis, and NIR. This work is carried out to solve the drawbacks of other studs that prepare detectors in just one or two optical regions. Previous studies have used high-priced techniques. The deposition of P3MA on the glass surface was carried out by in situ oxidation process. Then, this polymer film was used to assist the deposition of PbS-QD particles through the ionic adsorption deposition method. The latter was performed using four different concentrations of Pb(NO3)2 solution (0.01, 0.03, 0.05, and 0.07 M) to form four P3MA/PbS composites: I, II, III, and IV, respectively. The chemical structure, morphologies, and electrical and optical properties of these composites were determined using different analytical tools. The SEM confirmed the formation of spherical QD particles of PbS on the P3MA surface. The TEM analysis showed that the composite has an average size of 5 nm, with the interatomic distances of 0.4 nm. Furthermore, the optical band gap values were 1.53, 1.52, 1.50, and 1.51 eV, respectively. The optoelectronic device could detect and sense light from 390 to 636 nm under various optical wavelengths. The produced current density (Jph) values decreased from 0.029 mA.cm-2 at 390 nm to 0.022 mA.cm-2 at 500 nm and then increased until 0.024 mA.cm-2 at 636 nm. The light sensing was determined through the photoresponsivity (R) and detectivity (D) parameters, in which the photodetector has R and D values of 0.29 mA.cm-2 and 6.5×107 Jones, respectively. Finally, a simple mechanism was proposed to explain the light sensing through the prepared optoelectronic device. Soon, our team works on the industrial applications of this optoelectronic device in the industry field related to the great optoelectronic device technical properties and its low cost and easy preparation.

Polyaniline (PANI) and PANI/Ag2O/Ag composites I and II were prepared under different AgNO3 oxidant concentrations using the oxidative photopolymerization method. The chemical structure and optical, electrical, and morphological properties were determined for the prepared nanocomposite. The PANI/Ag2O/Ag composite II has the optimum optical properties, in which the bandgaps of PANI, composite I, and composite II are 3.02, 1.71, and 1.68 eV, respectively, with the morphology of a bunch of grape-like shapes with average particles sizes of 25 nm. Under the optimum optical properties, glass/PANI/Ag2O/Ag composite II electrode is used for hydrogen generation from sewage water. The measurements are carried out from a three-electrode cell under a xenon lamp. The effects of light wavelengths and temperature on the produced current density (Jph) are mentioned. Under the applied voltage (at 30°C), the current density values (Jph) increase from 0.003 to 0.012 mA.cm-2 in dark and light, respectively. While increasing the temperature, Jph values increase to 0.032 mAcm-2 at 60°C. The thermodynamic parameters are calculated, in which the activation energy (Ea), enthalpy (ΔH∗), and entropy (ΔS∗) values are 27.1 kJ·mol-1, 24.5 J mol-1, and 140.5 J K-1 mol-1, respectively. Finally, a simple mechanism for the produced hydrogen generation rate is mentioned. The prepared electrode is a very cheap (1$ for 12∗12 cm2) electrode.

Polyaniline-assisted deposition of PbS is carried out on antimony tin oxide (ATO) glass for ATO/PANI/PbS composite formation. The deposition of PbS was carried out inside and outside the polymer chains using the ionic adsorption deposition process. Various analyses were conducted to confirm the chemical structure and morphological, optical, and electrical properties of the resulting composite. TEM and SEM analyses demonstrated the spherical shape of PbS particles inside and outside the PANI network with more dark or white color, respectively. Moreover, the ImageJ program confirmed the composite formation. The XRD characterization showed the shifts in the PANI peaks after the composite formation with the appearance of a new additional peak related to PbS nanoparticles. The optical analyses were massively enhanced after the composite formation with more broadening in the Vis region at 630 nm, in which there was more enhancement in the bandgap that reached 1.5 eV. The electrode application in the H2 generation process was carried out from wastewater (sewage water, third treatment) without any additional sacrificing agent. The electrode responded well to light, where the current density (Jph) changed from 10-6 to 0.13 mA.cm-2 under dark and light, respectively. The electrode had high reproducibility and stability. The numbers of generated H2 moles were 0.1 mmol/cm2.h. The produced ΔH∗ and ΔS∗ were 7.3 kJ/mol and 273.4 J/mol.K, respectively. Finally, the mechanism explains the H2 generation reaction using three-electrode cell.

Graphitic carbon nitride (G-C3N4) and NiS-NiO/G-C3N4 nanocomposite have been synthesized via combustion and hydrothermal techniques, respectively. The chemical and morphological properties of these materials were confirmed using different analytical methods. SEM confirms the formation of G-C3N4 sheets containing additional petal-like shapes of NiS-NiO nanoparticles. The electrochemical testing of NiS-NiO/G-C3N4 symmetric supercapacitors is carried out from 0.6 M HCl electrolyte. Such testing includes charge/discharge, cyclic voltammetry, impedance, and supercapacitor stability. The charge/discharge time reaches 790 s at 0.3 A/g, while the cyclic voltammetry curve forms under a high surface area. The produced specific capacitance (CS) and energy density values are 766 F/g and 23.55 W.h.kg−1, correspondingly.

Graphitic carbon nitride (G-C3N4) was synthesized through the direct combustion of urea in the air. The CoS-Co2O3/G-C3N4 composite was synthesized via the hydrothermal method of G-C3N4 using cobalt salts. The morphological and chemical structures were determined through XRD, XPS, SEM, and TEM. XRD and XPS analyses confirmed the chemical structure, function groups, and elements percentage of the prepared nanocomposite. SEM measurements illustrated the formation of G-C3N4 sheets, as well as the flower shape of the CoS-Co2O3/G-C3N4 composite, evidenced through the formation of nano appendages over G-C3N4 sheets. TEM confirmed the 2D nanosheets of G-C3N4 with an average width and length of 80 nm and 170 nm, respectively. Two symmetric electrodes for the supercapacitor from the CoS-Co2O3/G-C3N4 composite. Electrochemical measurements were carried out to determine the charge/discharge, cyclic voltammetry, stability, and impedance of the prepared supercapacitor. The measurements were carried out under acid (0.5 M HCL) and basic (6.0 M NaOH) mediums. The charge and discharge lifetime values in the acid and base medium were 85 and 456 s, respectively. The cyclic voltammetry behavior was rectangular in a base medium for the pseudocapacitance feature. The supercapacitor had 100% stability retention up to 600 cycles; then, the stability decreased to 98.5% after 1000 cycles. The supercapacitor displayed a specific capacitance (CS) of 361 and 92 F/g, and an energy density equal to 28.7 and 30.2 W h kg−1 in the basic and acidic mediums, respectively. Our findings demonstrate the capabilities of supercapacitors to become an alternative solution to batteries, owing to their easy and low-cost manufacturing technique.

This study considers the progress of our previous study for hydrogen generation depends on the highly ordered metal oxide/plasmonic materials. This study reports the preparation of Ag2O-Ag/Au on the Al2O3 template (Ag2O-Ag/Au/Al2O3) for photocatalytic sewage water splitting and H2 gas production. Ni imprinting, followed by two-step anodization procedures, prepare the Al2O3 template. Ag2O-Ag and Au materials are prepared inside the template using electrochemical deposition and sputter coating methods, respectively. The chemical structure is confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses, in which all the peaks characterized by Ag2O, Ag, Au, and Al2O3 are confirmed. The scanning electron microscope (SEM) images confirm the preparation of a highly ordered hexagonal Al2O3 template with a pore wide of about 350 nm. Ag2O-Ag/Au accept the same morphology after the deposition process, in which the materials are deposited inside and on the Al2O3 template, in which the hexagonal pores are still opened after the deposition process. These open pores increase the surface area and then enhance the optical and electrical properties. For the H2 generated from sewage water, the produced Ag2O-Ag/Au on the Al2O3 photoelectrode achieved an incident to photon conversion efficiency (IPCE) of 30%. Additionally, the impact of light wavelength and intensity on photoelectrode performance is evaluated. Under increasing the light total power from 25 to 75 mW.cm−2, the current density (Jph) value goes up from 8.9 to 9.5 mA.cm−2. The current study’s findings show promising results for resolving the issue of energy in remote areas by turning wastewater into hydrogen fuel.

A novel photodetector, based on Cu2ZnSnS4, CZTS, is deposited on Cu/CuFeO2 for wavelength and light power intensity detection. The preparation of CuFeO2 is carried out by the direct combustion of Cu foil wetted with Fe(NO3)2 solution. The preparation of CZTS is carried out using the hydrothermal method, then it is dropped on CuFeO2 using the drop casting method at 70 °C. Various analyses are used to look at the chemical, morphological, and optical aspects of the Cu/CuFeO2/CZTS, such as UV–vis, SEM, TEM, selected-area electron diffraction, and XRD, in which all characteristic peaks are confirmed for the prepared materials. The Cu/CuFeO2/CZTS thin film’s SEM image has a homogeneous morphology, with particles that are around 350 nm in size, demonstrating a significant improvement in morphology over Cu/CuFeO2/CZTS thin film. The TEM analysis verified the nanostructured morphology of Cu/CuFeO2/CZTS. From XRD analysis of Cu/CuFeO2/CZTS, the high intensity of the generated peaks indexed to hexagonal (2H) CuFeO2 and kesterite CZTS crystal structures revealed a compact highly crystal material. From optical analysis, CZTS, Cu/CuFeO2, and Cu/CuFeO2/CZTS thin films recoded band gaps of 1.49, 1.75, and 1.23 eV, respectively. According to the band gap measurements, the optical absorption of the Cu/CuFeO2/CZTS photodetector has clearly increased. The Cu/CuFeO2/CZTS as photodetector has a detectivity (D) and responsivity (R) of 1.7 × 1010 Jones and 127 mAW−1, respectively. Moreover, the external quantum efficiency (EQE) is 41.5% at 25 mW·cm−2 and 390 nm. Hence, the prepared Cu/CuFeO2/CZTS photodetector has a very high photoelectrical response, making it very promising as a broadband photodetector.

Herein, an optoelectronic device synthesized from a CuFeO2/CuO/Cu nanocomposite was obtained through the direct combustion of Cu foil coated with Fe2O3 nanomaterials. The chemical, morphological, and optical properties of the nanocomposite were examined via different techniques, such as XRD, XPS, TEM, SEM, and UV/Vis spectrophotometer. The optical reflectance demonstrated a great enhancement in the CuFeO2 optical properties compared to CuO nanomaterials. Such enhancements were clearly distinguished through the bandgap values, which varied between 1.35 and 1.38 eV, respectively. The XRD and XPS analyses confirmed the chemical structure of the prepared materials. The produced current density (Jph) was studied in dark and light conditions, thereby confirming the obtained optoelectronic properties. The Jph dependency to monochromatic wavelength was also investigated. The Jph value was equal to 0.033 mA·cm−2 at 390 nm, which decreased to 0.031 mA·cm−2 at 508 nm, and then increased to 0.0315 mA·cm−2 at 636 nm. The light intensity effects were similarly inspected. The Jph values rose when the light intensities were augmented from 25 to 100 mW·cm−2 to reach 0.031 and 0.05 mA·cm−2, respectively. The photoresponsivity (R) and detectivity (D) values were found at 0.33 mA·W−1 and 7.36 × 1010 Jones at 390 nm. The produced values confirm the high light sensitivity of the prepared optoelectronic device in a broad optical region covering UV, Vis, and near IR, with high efficiency. Further works are currently being designed to develop a prototype of such an optoelectronic device so that it can be applied in industry.

Two-dimensional (2D) materials have attracted significant attention with their high optical response due to their interesting and unique fundamental phenomena. A lateral 2D MoS2 nanosheets was prepared via a facile one-step electrophoretic deposition method on polyethylene terephthalate (PET)/ITO. These nanosheets have been used as photoelectrode materials for photoelectrochemical (PEC) hydrogen generation and optoelectronics. The chemical structure and morphology were confirmed using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), Raman, scanning electron microscope (SEM), and transmission electron microscopy (TEM). The optical absorbance of the 2D MoS2 nanosheets extended to the UV, Vis, and near-IR regions with a bandgap value of 1.59 eV. The testing of the prepared photoelectrode material, PET/ITO/MoS2, was carried out through a three-electrode system, in which the current density (Jph) value represents the rate of H2 gas evaluated. The Jph enhanced under light illumination compared to the dark conditions with values of 0.4 to 0.98 mA·cm−2, respectively. The produced photocurrent at V = 0 V was 0.44 mA·cm−2. This confirms the great abilities of the PET/ITO/MoS2 photoelectrode in light detection and hydrogen generation with high photoresponsivity values. Soon, our team will work on the development of a prototype of this three-electrode cell to convert the water directly into H2 fuel gas that could be applied in houses and factories, or even in advanced technology such as spacecraft and airplane F-35s by providing H2 gas as a renewable energy source.

Porous anodic alumina membranes coated with Pt nanoparticles (PAAM/Pt) have been employed as pH sensor electrodes for H+ ion detection. The PAAM was designed using a two-step anodization process. Pt nanoparticles were then sputtered onto the membrane at different deposition times. The membrane’s morphological, chemical, and optical characteristics were carefully assessed following the fabrication stage using a variety of analytical techniques. The potential of the PAAM/Pt sensor electrode was investigated by measuring the potential using a simple potentiometric method. The effects of depositing Pt nanoparticles for 3–7 min on sensor electrode sensitivity were examined. The optimal potentiometric Nernstian response slope for the PAAM/Pt sensor electrode with 5 min Pt sputter coating is 56.31 mV/decade in the pH range of 3.0 to 10 at 293 K. Additionally, the PAAM/Pt sensor electrode’s stability and selectivity in various ions solutions were examined. The sensor electrode had a lifetime of more than six weeks and was kept in a normal air environment.

Nanoporous Graphene Oxide (NGO) film sensor is designed by combining the modified Hummer method and the spray pyrolysis technique. The structural, morphological, and optical characterizations of the prepared NGO sensor are carried by FTIR, XRD, SEM, and UV–vis spectrophotometer. Based on the morphological study, a homogenous and uniform NGO film with two-dimensional nanoporous structure is prepared. The structural study reveals the existence of high density of oxygen functional groups on a typical GO surface with d-spacing ˜0.82 nm. The optical characterization shows intensive and broad absorption band around 335 nm. The NGO film is used as a detector for CO2, H2, C2H2 gases at room temperature (20 °C). The response, response and recovery times, and selectivity of the NGO sensor are investigated. Also, the effect of gases concentrations on the resistance of the film is studied. The response and selectivity of the NGO film are in order CO2 > H2 > C2H2. The sensor response is 37.04, 16.16, and 2.87% at 60 SCCM for CO2, H2, and C2H2, respectively. The response time is ˜25, 100, and 100 s @ 10 SCCM for CO2, H2, and C2H2, respectively. At concentrations of 30 SCCM, the recovery time is 241.4, 437.2, and 674.7 s for C2H2, H2, and CO2, respectively. Finally, a simple mechanism is explained to show the sensing approach. Keywords: Gas sensor, Graphene oxide, Nanostructures, Carbon dioxide, Hydrogen, Acetylene

This study is very promising for providing a renewable enrgy (H2 gas fuel) under the elctrochemical splitting of the wastwater (sewage water). This study has double benefits: hydrogen generation and contaminations removel. This study is carried out on sewage water, third stage treated, from Beni-Suef city, Egypt. Antimony tin oxide (ATO)/polyaniline (PANI)/PbI2 photoelectrode is prepared through the in situ oxidative polymerization of PANI on ATO, then PANI is used as an assistant for PbI2 deposition using the ionic adsorption deposition method. The chemical structural, morphological, electrical, and optical properties of the composite are confirmed using different analytical tools such as X-ray diffreaction (XRD), scanning electron microscope (SEM), transmision electron microscope (TEM), Fourier-transform infrared spectroscopy (FTIR), and UV-Vis spectroscopy. The prepared PbI2 inside the composite has a crystal size of 33 nm (according to the peak at 12.8°) through the XRD analyses device. SEM and TEM confirm the hexagonal PbI2 sheets embedded on the PANI nanopores surface. Moreover, the bandgap values are enhanced very much after the composite formation, in which the bandgap values for PANI and PANI/PbI2 are 3 and 2.51 eV, respectively. The application of ATO/PANI/PbI2 nanocomposite electrode for sewage splitting and H2 generation is carried out through a three-electrode cell. The measurements carreid out using the electrocehical worksattion under th Xenon lamp (100 mW.cm−2). The produced current density (Jph) is 0.095 mA.cm−2 at 100 mW.cm−2 light illumination. The photoelectrode has high reproducibility and stability, in which and the number of H2 moles is 6 µmole.h−1.cm−1. The photoelectrode response to different monochromatic light, in which the produced Jph decreases from 0.077 to 0.072 mA.cm−2 with decreasing of the wavelengths from 390 to 636 nm, respectively. These values confirms the high response of the ATO/PANI/PbI2 nanocomposite electrode for the light illuminaton and hydrogen genration under broad light region. The thermodynamic parameters: activation energy (Ea), enthalpy (ΔH*), and entropy (ΔS*) values are 7.33 kJ/mol, −4.7 kJ/mol, and 203.3 J/mol.K, respectively. The small values of ΔS* relted to the high sesnivity of the prepared elctrode for the water splitting and then the hydrogen gneration. Finally, a theoretical study was mentioned for calculation geometry, electrochemical, and thermochemistry properties of the polyaniline/PbI2 nanocomposite as compared with that for the polyaniline.

This work reports on H2 fuel generation from sewage water using Cu/CuO nanoporous (NP) electrodes. This is a novel concept for converting contaminated water into H2 fuel. The preparation of Cu/CuO NP was achieved using a simple thermal combustion process of Cu metallic foil at 550 °C for 1 h. The Cu/CuO surface consists of island-like structures, with an inter-distance of 100 nm. Each island has a highly porous surface with a pore diameter of about 250 nm. X-ray diffraction (XRD) confirmed the formation of monoclinic Cu/CuO NP material with a crystallite size of 89 nm. The prepared Cu/CuO photoelectrode was applied for H2 generation from sewage water achieving an incident to photon conversion efficiency (IPCE) of 14.6%. Further, the effects of light intensity and wavelength on the photoelectrode performance were assessed. The current density (Jph) value increased from 2.17 to 4.7 mA·cm−2 upon raising the light power density from 50 to 100 mW·cm−2. Moreover, the enthalpy (ΔH*) and entropy (ΔS*) values of Cu/CuO electrode were determined as 9.519 KJ mol−1 and 180.4 JK−1·mol−1, respectively. The results obtained in the present study are very promising for solving the problem of energy in far regions by converting sewage water to H2 fuel.

This study provides H2 gas as a renewable energy source from sewage water splitting reaction using a PMT/Au photocathode. So, this study has a dual benefit for hydrogen generation; at the same time, it removes the contaminations of sewage water. The preparation of the PMT is carried out through the polymerization process from an acid medium. Then, the Au sputter was carried out using the sputter device under different times (1 and 2 min) for PMT/Au-1 min and PMT/Au-2min, respectively. The complete analyses confirm the chemical structure, such as XRD, FTIR, HNMR, SEM, and Vis-UV optical analyses. The prepared electrode PMT/Au is used for the hydrogen generation reaction using Na2S2O3 or sewage water as an electrolyte. The PMT crystalline size is 15 nm. The incident photon to current efficiency (IPCE) efficiency increases from 2.3 to 3.6% (at 390 nm), and the number of H2 moles increases from 8.4 to 33.1 mmol h−1 cm−2 for using Na2S2O3 and sewage water as electrolyte, respectively. Moreover, all the thermodynamic parameters, such as activation energy (Ea), enthalpy (ΔH*), and entropy (ΔS*), were calculated; additionally, a simple mechanism is mentioned for the water-splitting reaction.

In this work, a polyaniline/lead sulfide (PANI/PbS) nanocomposite was prepared by combining the in situ oxidation polymerization method and the surface adsorption process. This nanocomposite was applied as a supercapacitor electrode. The crystal structure, nanomorphology, and optical analysis of PANI and PANI/PbS were investigated. The electrochemical performance of the designed PANI/PbS electrode-based supercapacitor was tested by using cyclic voltammetry (CV), chronopotentiometry (CP), and AC impedance techniques in HCl and Na2SO4 electrolytes. The average crystallite size of the PANI/PbS nanocomposite is about 43 nm. PANI/PbS possesses an agglomerated network related to PANI with additional spherical shapes from PbS nanoparticles. After the PANI/PbS nanocomposite formation, there are enhancements in their absorption intensities. At a current density of 0.4 A g−1, the specific capacitance of PANI/PbS in Na2SO4 and HCl was found to be 303 and 625 F g−1, respectively. In HCl (625 F g−1 and 1500 mF cm−2), the gravimetric and areal capacitances of the PANI/PbS electrode are nearly double those of the Na2SO4 electrolyte. Also, the average specific energy and specific power density values for the PANI/PbS electrode in HCl are 4.168 Wh kg−1 and 196.03 W kg−1, respectively. After 5000 cycles, the capacitance loses only 4.5% of its initial value. The results refer to the high stability and good performance of the designed PANI/PbS as a supercapacitor electrode.

Thin films of ZnO and ZnO/carbon nanotubes (CNTs) are prepared and used as CO2 gas sensors. The spray pyrolysis method was used to prepare both ZnO and ZnO/CNTs films, with CNTs first prepared using the chemical vapor deposition method (CVD). The chemical structure and optical analyses for all the prepared nanomaterials were performed using X-ray diffraction (XRD), Fourier transformer infrared spectroscopy (FTIR), and UV/Vis spectrophotometer devices, respectively. According to the XRD analysis, the crystal sizes of ZnO and ZnO/CNTs were approximately 50.4 and 65.2 nm, respectively. CNTs have average inner and outer diameters of about 3 and 13 nm respectively, according to the transmitted electron microscope (TEM), and a wall thickness of about 5 nm. The detection of CO2 is accomplished by passing varying rates of the gas from 30 to 150 sccm over the prepared thin-film electrodes. At 150 sccm, the sensitivities of ZnO and ZnO/CNTs sensors are 6.8% and 22.4%, respectively. The ZnO/CNTs sensor has a very stable sensitivity to CO2 gas for 21 days. Moreover, this sensor has a high selectivity to CO2 in comparison with other gases, in which the ZnO/CNTs sensor has a higher sensitivity to CO2 compared to H2 and C2H2.

An aluminum oxide, Al2O3, template is prepared using a novel Ni imprinting method with high hexagonal pore accuracy and order. The pore diameter after the widening process is about 320 nm. TiO2 layer is deposited inside the template using atomic layer deposition (ALD) followed by the deposition of 6 nm TiN thin film over the TiO2 using a direct current (DC) sputtering unit. The prepared nanotubular TiN/TiO2/Al2O3 was fully characterized using different analytical tools such as X-ray diffraction (XRD), Energy-dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM), and optical UV-Vis spectroscopy. Exploring the current-voltage relationships under different light intensities, wavelengths, and temperatures was used to investigate the electrode’s application before and after Au coating for H2 production from sewage water splitting without the use of any sacrificing agents. All thermodynamic parameters were determined, as well as quantum efficiency (QE) and incident photon to current conversion efficiency (IPCE). The QE was 0.25% and 0.34% at 400 mW·cm−2 for the photoelectrode before and after Au coating, respectively. Also, the activation energy was 27.22 and 18.84 kJ·mol−1, the enthalpy was 24.26 and 15.77 J·mol−1, and the entropy was 238.1 and 211.5 kJ−1·mol−1 before and after Au coating, respectively. Because of its high stability and low cost, the prepared photoelectrode may be suitable for industrial applications.

The versatility of high-density polyethylene (HDPE) makes it one of the most used polymers for vast applications ranging from food packaging to human implants. However, there still is confusion regarding the proper selection of processing techniques to produce HDPE specimens for high-end applications. Herein, we compare the processing of HDPE by two relevant techniques: compression and injection molding. The fabricated samples were studied using uniaxial tensile testing to determine their mechanical performance. Furthermore, the microstructure of samples was analyzed using different characterization techniques. Compression-molded specimens recorded a higher degree of crystallinity (DC) using two different characterization techniques such as differential scanning calorimetry (DSC) and X-ray diffraction (XRD). With this information, critical processing factors were determined, and a general structure–property relationship was established. It was demonstrated that having a higher DC resulted in higher yield strength and Young’s modulus. Furthermore, premature failure was observed in the injection-molded specimens, resulting in lower mechanical performance. This premature failure was caused due to flow marks observed using scanning electron microscopy (SEM). Therefore, it is concluded that compression molding produces superior samples compared to injection molding.