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 (J_ph) 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 utilized the exceptional optical and electrical properties of polypyrrole (Ppy) to fabricate high-performance optoelectronic devices. The synthesis of the porous-spherical Cr₂O₃-Cr(OH)₃-Ppy/Ppy nanocomposite thin film was achieved by preparing a second thin film of Cr₂O₃-Cr(OH)₃-Ppy on the initial Ppy film using K₂Cr₂O₇ as an oxidant. The nanocomposite’s properties were thoroughly characterized, including XRD and optical absorbance analyses. The XRD analysis showed that the crystalline size of the nanocomposite was 20 nm, while optical absorbance analysis demonstrated that the nanocomposite had a higher absorbance in a wide optical range compared to Ppy nanomaterials, as evidenced by the enhancement in bandgap (Eg) value from 3.33 eV for Ppy to 1.89 eV for Cr₂O₃-Cr(OH)₃-Ppy. The fabricated nanocomposite thin film exhibited excellent light-sensing behavior, as evidenced by the evaluation of J_ph values under different light conditions and various monochromatic lights with a detectivity (D) of 3.6 × 10⁶ Jones (at 340 nm). The device demonstrated its potential as a solar cell, with a short circuit current (J_SC) of 13 µA and an open circuit voltage (V_OC) of 1.91 V. Given the nanocomposite’s low cost, high technical production, and superior optoelectronic properties, it has significant potential for use in commercially available high-tech devices.

This paper describes the establishment of free-standing rolled graphene oxide (roll-GO) and polypyrrole (Ppy) using a modified Hummer method and oxidative polymerization. Then, a photodetector was created by removing a thin film of the free-standing rolled graphene oxide from a filter paper and attaching it to a tape. The chemical structure of the roll-GO was confirmed using XRD and FTIR analysis, while SEM and TEM showed that it was rolled in nature. The material had a small bandgap of 2.4 eV and a high current density in light conditions. The photodetector responded well to monochromatic light, with J_ph values changing from 0.027 to 0.019 mA/cm² as the light wavelengths decreased from 340 to 730 nm. The photoresponsivity (R) and detectivity (D) values were high, at 340 nm (0.27 mA/W and 6.0 × 10⁷ Jones, respectively) and at 730 nm (0.19 and 4.25 × 10⁷ Jones, respectively). The addition of Ppy improved these parameters, with the Ppy/roll-GO/tape photoelectrode showing excellent R and D values of 0.33 mA/W and 7.34 × 10⁷ Jones, respectively. Furthermore, the production of a photocurrent at V = 0 indicated that the Ppy/roll-GO layer could be used for solar cell applications. Overall, the results suggest that the prepared free-standing Ppy/roll-GO/tape photodetector has high potential for use in the optical region between 340 and 730 nm and may be suitable for industrial applications.

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.

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 (J_ph) 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 J_ph 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.