BaTiO3 Functional Perovskite as Photocathode in Microbial Fuel Cells for Energy Production and Wastewater Treatment.

Microbial fuel cells (MFCs) provide new opportunities for the sustainable production of energy, converting organic matter into electricity through microorganisms. Moreover, MFCs play an important role in remediation of environmental pollutants from wastewater with power generation. This work focuses on the evaluation of ferroelectric perovskite materials as a new class of non-precious photocatalysts for MFC cathode construction. Nanoparticles of BaTiO3 (BT) were prepared and tested in a microbial fuel cell (MFC) as photocathode catalytic components. The catalyst phases were synthesized, identified and characterized by XRD, SEM, UV-Vis absorption spectroscopy, P-E hysteresis and dielectric measurements. The maximum absorption of BT nanoparticles was recorded at 285 nm and the energy gap (Eg) was estimated to be 3.77 eV. Photocatalytic performance of cathodes coated with BaTiO3 was measured in a dark environment and then in the presence of a UV-visible (UV-Vis) light source, using a mixture of dairy industry and domestic wastewater as a feedstock for the MFCs. The performance of the BT cathodic component is strongly dependent on the presence of UV-Vis irradiation. The BT-based cathode functioning under UV-visible light improves the maximum power densities and the open circuit voltage (OCV) of the MFC system. The values increased from 64 mW m-2 to 498 mW m-2 and from 280 mV to 387 mV, respectively, showing that the presence of light effectively improved the photocatalytic activity of this ceramic. Furthermore, the MFCs operating under optimal conditions were able to reduce the chemical oxygen demand load in wastewater by 90% (initial COD = 2500 mg L-1).

Electrochemical Detection of Sulfadiazine by Sensors based on Chemically Modified Carbon Electrodes: A Review.

The consumption of medicines (usually pharmaceuticals and chemical health products) has increased in recent decades due to the demand for medicines for various diseases (headache, relapsing fever, dental absence, streptococcal infection, bronchitis, ear and eye infections). Instead, their overuse can lead to serious environmental damage. Sulfadiazine is one of the most often used antimicrobial medications for both human and veterinary therapy, yet its presence in the environment, even in low quantities, offers a potential concern as an emergency pollutant. It is vital to have a monitoring that's quick, selective, sensitive, stable, reversible, reproducible, and easy to use. Electrochemical techniques realizing cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square wave voltammetry (SWV), using a modified electrode based on carbon as a surface modifier are an excellent option that makes control simple and quick owing to their cheap cost and convenience of use, while also safeguarding human health from drug residue buildup. This study discusses different chemically modified carbon-based electrodes such as graphene paste, screen printed electrode, glassy carbon, and boron diamond doped electrodes for SDZ (sulfadiazine) detection in various formulation feeds, pharmaceuticals, milk, and urine samples, the results obtained also show high sensitivity and selectivity with lower detection limits compared to matrix studies, which may explain its use in trace detection. Furthermore, the effectiveness of the sensors is assessed by other parameters including buffer solution, scan rate, and pH. Also, a method for real sample preparation was also discussed in addition to the different methods mentioned.