Dye-sensitized solar cells (DSSCs) are a feasible option for photovoltaic energy. Zinc oxide is an n-type semiconductor employed as photoanode on DSSCs. ZnO thin films were electrodeposited to study the effects of different potentials applied during deposition. SEM images, XRD and UV-Vis analysis were conducted to reveal the morphologic, structural and optical properties of the films at three potentials. DSSCs were assembled and the photovoltaic parameters were obtained through J-V plots. DSSC with 0.031% of efficiency was demonstrated at -1.4 V of deposition potential.

The aim of this research was to estimate the production of hydrogen, organic acids and alcohols by the strain of Clostridium acetobutylicum ATCC 824 using residual glycerol as a carbon source. The experiments were carried out in pure and mixed cultures in batch experiments. Three different sources of inocula for mixed culture were used. Ruminal liquid from goats and sludge collected from two upflow anaerobic sludge blanket reactors treating municipal wastewater and brewery effluent were tested for hydrogen, organic acids and alcohols production with or without C. acetobutylicum ATCC 824. The main detected end-products from the glycerol fermentation were hydrogen, organic acids (acetic, propionic, butyric and caproic) and alcohol (ethanol and 1,3-propanediol – 1,3PD). High hydrogen (0.44 mol H₂/mol glycerol consumed) and 1,3PD (0.32 mol 1,3PD/mol glycerol consumed) yields were obtained when the strain C. acetobutylicum ATCC 824 was bioaugmented into the sludge from municipal wastewater using 5 g/L of glycerol. Significant concentrations of n-caproic acid were detected in the ruminal liquid when amended with C. acetobutylicum ATCC 824. The results suggest that glycerol can be used for the generation of H₂, 1,3PD and n-caproic acid using C. acetobutylicum ATCC 824 as agent in pure or mixed cultures.

Nanoparticles of TiO₂ have been the main semiconductor applied in Dye-sensitized solar cells (DSSCs). In this work, titanate nanotubes (NaTiNT) and nanoribbons, were obtained by the hydrothermal method from TiO₂ anatase. These materials were deposited on conductive substrate by electrophoresis, with and without thermal treatment, sensitized by ruthenium-based dye and used as work electrode. Exposing those photovoltaic devices to visible radiation, with films before thermal treatment, a short-circuit current density (J_SC) of 0.0012 mA/cm² was observed for the cell with NaTiNT, a current density of 0.0398 mA/cm² for the cell with Nanoribbons, and a current density of 0.4028 mA/cm² for the cell with TiO₂ as electrode. After thermal treatment, a short-circuit current density of 0.4269 mA/cm² was observed for the cell with NaTiNT, a current density of 0.0765 mA/cm² for the Nanoribbons cell, and, finally, a current density of 0.3310 mA/cm² for the cell with TiO₂ as electrode. The new morphological, structural and optical characteristics of these nanoparticles may contribute for the development and research of new generation photovoltaic devices.

Electrophoretic deposition is a straightforward, environmentally friendly, and cost-effective technique for depositing and synthesizing nanomaterials, particularly nanofilms of semiconductors. Key parameters in electrophoresis include deposition time and voltage. Zinc oxide, a semiconductor of significant interest in solar energy research, possesses favorable characteristics, notably, a band gap value of approximately 3.33 eV. In the realm of dye-sensitized solar cells, which represent the third generation of solar cells, zinc oxide has emerged as a compelling choice for a photoanode. This study focused on depositing thin films of zinc oxide through electrophoresis and applying them as photoanodes in dye solar cells. The results demonstrated that the electrodeposited films exhibited good reflectance in the visible spectrum (~60–90%), a band gap energy of 3.28 eV, and an incident photon conversion efficiency of approximately 4.48% for the electrodeposited film at 80 V for 5 min.