Metal oxide nanoparticles have recently garnered interest as potentially valuable substances for the management of plant diseases. Copper oxide nanoparticles (Cu₂ONPs) were chemically fabricated to control root rot disease in cucumbers. A scanning electron microscope (SEM), X-ray diffraction (XRD) and photoluminescence (PL) were employed to characterize the produced nanoparticles. Moreover, the direct antifungal activity of Cu₂ONPs against Fusarium solani under laboratory, greenhouse, and field conditions were also evaluated. In addition, the induction of host-plant resistance by Cu₂ONPs was confirmed by the results of enzyme activities (catalase, peroxidase, and polyphenoloxidase) and gene expression (PR-1 and LOX-1). Finally, the effect of Cu₂ONPs on the growth and productivity characteristics of the treated cucumber plants was investigated. The average particle size from all the peaks was found to be around 25.54 and 25.83 nm for 0.30 and 0.35 Cu₂O, respectively. Under laboratory conditions, the study found that Cu₂ONPs had a greater inhibitory effect on the growth of Fusarium solani than the untreated control. Cu₂ONP treatment considerably reduced the disease incidence of the root rot pathogen in cucumber plants in both greenhouse and field environments. Defense enzyme activity and defense genes (PR1 and LOX1) transcription levels were higher in cucumber plants treated with Cu₂ONPs and fungicide than in the untreated control. SEM analysis revealed irregularities, changes, twisting, and plasmolysis in the mycelia, as well as spore shrinking and collapsing in F. solani treated with Cu₂ONPs, compared to the untreated control. The anatomical analysis revealed that cucumber plants treated with Cu₂ONPs had thicker cell walls, root cortex, and mesophyll tissue (MT) than untreated plants. Cucumber growth and yield characteristics were greatly improved after treatment with Cu₂ONPs and fungicide. To the best of our knowledge, employing Cu₂ONPs to treat cucumber rot root disease is a novel strategy that has not yet been reported.

ZrS₂ is transition metal dichalcogenides (TMDCs) which is believed one of the most talented applicants to fabricate photovoltaics. Therefore, we present here for the first-time numerical simulation of novel inorganic ZrS₂/CuO heterojunction solar cells employing SCAPS-1D. The influence of the thickness, carrier concentration, and bandgap for both the window and absorber layers on the solar cell fundamental parameters was explored intensely. Our results reveal that the solar cell devices performance is mainly affected by many parameters such as the depletion width (W_d), built-in voltage (V_bi), collection length of charge carrier, the minority carrier lifetime, photogenerated current, and recombination rate. The η of 23.8% was achieved as the highest value for our simulated devices with the V_oc value of 0.96 V, the J_sc value of 34.2 mA/cm², and the FF value of 72.2%. Such efficiency was obtained when the CuO band gap, thickness, and carrier concentration were 1.35 eV, 5.5 µm, and above 10¹⁸ cm⁻³, respectively, and for the ZrS₂ were 1.4 eV, 1 µm, and less than 10²⁰ cm⁻³, respectively. Our simulated results indicate that the inorganic ZrS₂/CuO heterojunction solar cells are promising to fabricate low-cost, large-scale, and high-efficiency photovoltaic devices.

Zinc Oxide (ZnO) nanorods have great potential in several applications including gas sensors, light-emitting diodes, and solar cells because of their unique properties. Here, three low cost and ecofriendly techniques were used to produce ZnO nanorods on FTO substrates: hydrothermal, chemical bath deposition (CBD), and electrochemical deposition (ECD). This study explores the impact of such methods on the optical, structural, electrical, morphological, and photoelectrochemical properties of nanorods using various measurements. XRD analysis confirmed the hexagonal wurtzite structure of ZnO nanorods in all three methods, with hydrothermal showing a preferred orientation (002) and CBD and ECD samples showing multiple growth directions, with average particle sizes of 31 nm, 34 nm, and 33 nm, respectively. Raman spectra revealed hexagonal Wurtzite structure of ZnO, with hydrothermal method exhibiting higher E₂ (high) peak at 438 cm⁻¹ than CBD and ECD methods. SEM results revealed hexagonal ZnO nanorods became more regular and thicker for the hydrothermal method, while CBD and ECD led to less uniform with voids. UV-vis spectra showed absorption lines between 390 nm and 360 nm. Optical bandgap energies were calculated as 3.32 eV, 3.22 eV, and 3.23 eV for hydrothermal, CBD, and ECD samples, respectively. PL spectra revealed UV emission band with a small intensity peak around 389 nm and visible emission peaks at 580 nm. Temperature dependent PL measurements for ZnO nanorods indicated that the intensities ratio between bound exciton and free exciton decreases with temperature increases for the three methods. Photocurrent measurements revealed ZnO nanorod films as n-type semiconductors, with photocurrent values of 2.25 µA, 0.28 µA, and 0.3 µA for hydrothermal, CBD, and ECD samples, and photosensitivity values of 8.01, 2.79, and 3.56 respectively. Our results suggest that the hydrothermal method is the most effective approach for fabricating high-quality ZnO nanorods for optoelectronic applications.