Novel Removal of Diazinon Pesticide by Adsorption and Photocatalytic Degradation of Visible Light-Driven Fe-TiO₂/Bent-Fe Photocatalyst

Abstract

In the study, Fe was used as a dopant to enhance photocatalytic activity of TiO2. Then, the Fe-doped TiO2 was deposited on bentonite, which was pillared by Fe. The synthesized materials were characterized by SEM, XRD, UV-Vis, BET, and point of zero charge (pHPZC). Then, the synthesized materials were used for diazinon removal under both dark and visible light conditions to investigate adsorption and photocatalytic degradation abilities of the synthesized materials. The maximum diazinon adsorption capacity of the synthesized Fe-TiO2/Bent-Fe was 27.03 mg/g. The obtained results indicated that the Fe-TiO2/Bent-Fe exhibited high photocatalytic degradation activity for removal of diazinon even under visible light. The diazinon removal experiments were also conducted using different photocatalyst dosages, under different pH and light sources to figure the optimal conditions for removal processes. The obtained results indicated that optimal photocatalyst dosage and pH were 0.5 g/L and 4.5, respectively. Finally, the natural light generated from solar could be suitable used for diazinon removal by the synthesized Fe-TiO2/Bent-Fe.

Synthesis of Oxygen Deficient TiO2 for Improved Photocatalytic Efficiency in Solar Radiation

“…The associated high energy band gaps and agglomeration of TiO 2 severely limit its application as a photocatalyst in water treatment [4]. Sustainability of photo-degradation processes can be achieved by the synthesis of TiO 2 with enhanced capacity for solar-light harvesting through improvements in the documented disadvantages [8,9]. Common techniques such as modification by organic materials, semi-conductor coupling and metal doping can be employed to create surface defects on TiO 2 and consequently reduce the energy band gap and prevent the agglomeration [10].…”

Mitigation of Diclofenac Pollution in Aqueous Media by Adsorption

“…Phuong et al. used TiO 2 as photo‐catalyst, albeit for diazinon. Combining both processes has been shown to be quite effective as the photo‐catalytic process mineralizes the pollutant into non‐toxic form.…”

“…The combination of adsorption and photo-catalytic degradation has been investigated using hydrogen peroxide [87]. Phuong et al [90] used TiO 2 as photo-catalyst, albeit for diazinon. Combining both processes has been shown to be quite effective as the photo-catalytic process mineralizes the pollutant into non-toxic form.…”

The Development of Diazinon Sensors using Polyvinyl Alcohol (PVA) Membrane CuO on Surface Screen-Printed Carbon Electrode (SPCE) as a Receptor

“…As a result of the form of negatively charged molecule caused the signal is inversely proportional to the concentration of the analyte. in addition, the pKa of diazinon is 2.6, thus diazinon is negatively charged at 3, 4, and 5 pH conditions [43]. The solution under conditions close to base exacly at pH 4 affects the ions movement in the solution caused the decreased of conductivity [40].…”

“…The increase in ion strength is directly proportional to the capacitance and the use of Britton-Robinson buffer. It is possible to form electric double on the membrane surface which causes a capacitance that can reduce its potential, resulting to a smaller signal [43]. The lowest signal is produced by a phosphate buffer.…”