The increasing demand for functional nanodevices in sustainable energy applications necessitates the development of innovative approaches. In this study, we present the fabrication and characterization of three-dimensional (3D) structures coated with titanium dioxide (TiO2) nanorods (NRs). These novel devices are created through the integration of four distinct techniques, multi-photon lithography, post-thermal treatment, pulsed laser deposition, and an aqueous chemical growth, enabling their unique properties and functionalities in photocatalysis. The photocatalytic performance of the 3D devices is evaluated through the degradation of organic pollutants, such as methylene blue and stearic acid, showcasing their efficiency in reducing pollutant concentrations. The devices demonstrate a remarkable decomposition coefficient (k=0.059min−1), highlighting their enhanced photocatalytic efficiency. Additionally, we propose a rapid fabrication technique using 3D holographic printing to create large-area TiO2-coated micro-structured photocatalytic devices at the mesoscale regime. This approach increases the active surface area, further enhancing the devices’ photocatalytic capabilities. By combining additive micro-manufacturing, TiO2 NR coating, and holographic printing, our work introduces a promising avenue for the development of advanced nanodevices with superior photocatalytic performance in sustainable energy applications.

In an attempt to identify solutions to advance net-zero energy actions and accelerate the deployment of cutting-edge low-carbon technologies, hybrid approaches of synthesizing and engineering materials towards solar energy harvesting and management have been developed. In this work, two different forms of TiO2 were synthesized and applied as electron transfer layer (ETL) in perovskite solar cells (PSCs). In addition, double-doped NiO was combined with these two forms of TiO2 and the fabricated NiO/TiO2 heterostructures were examined for their photocatalytic activities against decolorization of methylene blue (MB) probe-molecule pollutant. The two forms of TiO2 were the 1-D TiO2 nanorods (TiO2-NRs), synthesized by an aqueous hydrothermal technique, and the 3-D mesoporous TiO2 (m-TiO2), synthesized by spin-coating. The NiO was fabricated by sputtering and after doping-engineering the optimum double-doped NiO:(Nb,N) was used to form the NiO/TiO2 heterostructures. The PSC formed by the 1-D TiO2-NRs as ETL exhibited under AM1.5 illumination the same open-circuit voltage but twice the short-circuit current when compared to the PSC having the conventional m-TiO2 as ETL. The photocatalytic activity of the 1-D NiO/TiO2 heterostructure with the NRs was 23% faster than the respective 3-D NiO/TiO2 heterostructure, inducing at the same time around 83% more (MB) degradation. The effect of the increased effective surface area of the 1-D heterostructures employing the NRs, along with the enhanced NiO-TiO2 diode properties favouring and enhancing the absorption and the rates of photocatalytic reactions are discussed. These results provide a direct comparison between heterostructures synthesized via hybrid routes for optoelectronic applications in the fields of energy harvesting and photocatalysis.

In an attempt to identify solutions to advance net-zero energy activities and accelerate the deployment of cutting-edge low-carbon technologies, hybrid approaches for solar energy harvesting and engineering materials have been developed. In this study, two different forms of TiO ₂ were synthesized and applied as electron transport layers (ETL) in perovskite solar cells (PSCs). In addition, double-doped sputtered NiO was used and the fabricated NiO/TiO ₂ heterostructures were examined for their photocatalytic activities against the decolorization of methylene blue (MB). The two forms of TiO ₂ were the one-dimensional (1D) TiO ₂ nanorods (TiO ₂ -NRs), synthesized using a hydrothermal technique, and the three-dimensional (3D) mesoporous TiO ₂ (m-TiO ₂ ) synthesized by spin-coating. The PSC formed by the 1D TiO ₂ -NRs as ETL showed the same open-circuit voltage under solar illumination but twice the short-circuit current when compared to the PSC having the conventional m-TiO ₂ as ETL. The photocatalytic activity of the 1D NiO/TiO ₂ -NRs heterostructure was 23 wt% faster than the respective 3D NiO/TiO ₂ one, while inducing about 83 wt% more MB degradation. These effects were attributed to the different effective surface areas and the diode properties of the NiO/TiO ₂ heterostructures. The presented results provide a direct comparison between heterostructures synthesized via hybrid routes for optoelectronic applications in the fields of energy harvesting and photocatalysis.