Effects of the Structure of TiO2 Nanotube Arrays on Its Catalytic Activity for Microbial Fuel Cell

Performance Enhancement of Actual Wastewater Treatment and Electricity Generation Through Surface Modified TiO₂ Nanotube Arrays Based Photoanode Photocatalytic Fuel Cell

Herein, we report a surface modified TiO₂ nanowire arrays (NAs) photoanode based photocatalytic fuel cell (PFC) towards simultaneous enhancement of actual wastewater treatment and electricity generation under visible light irradiation. TiO₂ NAs were facile fabricated via two-step anodization process in ethylene glycol and glycerin solution, respectively. Actual wastewater samples were directly applied to evaluate the PFC performance in terms of wastewater degradation and electricity generation through the as-prepared TiO₂ NAs photoanode without loading noble-metals or semiconductors. TiO₂ NAs photoanode prepared from ethylene glycol solution demonstrated a highly ordered surface network, exhibiting short-circuit current density and fill factor nearly 4.3 times and 1.4 times higher than pristine TiO₂ NAs photoanode prepared according to previous reports. The experimental results revealed that the fabrication of TiO₂ NAs by a facile surface modification in ethylene glycol solution can be considered a low-cost and scalable routine for enhancing performance of PFC photoanode towards efficient actual wastewater treatment and electricity generation.

The Use of Anodic Oxides in Practical and Sustainable Devices for Energy Conversion and Storage

This review addresses the main contributions of anodic oxide films synthesized and designed to overcome the current limitations of practical applications in energy conversion and storage devices. We present some strategies adopted to improve the efficiency, stability, and overall performance of these sustainable technologies operating via photo, photoelectrochemical, and electrochemical processes. The facile and scalable synthesis with strict control of the properties combined with the low-cost, high surface area, chemical stability, and unidirectional orientation of these nanostructures make the anodized oxides attractive for these applications. Assuming different functionalities, TiO2-NT is the widely explored anodic oxide in dye-sensitized solar cells, PEC water-splitting systems, fuel cells, supercapacitors, and batteries. However, other nanostructured anodic films based on WO3, CuxO, ZnO, NiO, SnO, Fe2O3, ZrO2, Nb2O5, and Ta2O5 are also explored and act as the respective active layers in several devices. The use of AAO as a structural material to guide the synthesis is also reported. Although in the development stage, the proof-of-concept of these devices demonstrates the feasibility of using the anodic oxide as a component and opens up new perspectives for the industrial and commercial utilization of these technologies.