Porphyrins and related macrocycles have been intensively exploited as sensing materials in chemical sensors, since in these devices they mimic most of their biological functions, such as reversible binding, catalytic activation, and optical changes. Such a magnificent bouquet of properties allows applying porphyrin derivatives to different transducers, ranging from nanogravimetric to optical devices, also enabling the realization of multifunctional chemical sensors, in which multiple transduction mechanisms are applied to the same sensing layer. Potential applications are further expanded through sensor arrays, where cross-selective sensing layers can be applied for the analysis of complex chemical matrices. The possibility of finely tuning the macrocycle properties by synthetic modification of the different components of the porphyrin ring, such as peripheral substituents, molecular skeleton, coordinated metal, allows creating a vast library of porphyrinoid-based sensing layers. From among these, one can...

Porphyrinoids for Chemical Sensor Applications.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ange.201102322

Angewandte Chemie International Edition feiert 50. Geburtstag

N,S co-doped carbon dots based fluorescent “on-off-on” sensor for determination of ascorbic acid in common fruits

Spinach thylakoids were immobilized onto multiwalled carbon nanotubes using a molecular tethering chemistry. The resulting thylakoid–carbon nanotube composites showed high photo-electrochemical activity under illumination. Multiple membrane proteins have been observed to participate in direct electron transfer with the electrode, resulting in the generation of photocurrents, the first of its kind reported for natural photosynthetic systems. Upon inclusion of a mediator, the photo-activity was enhanced. The major contributor to the photocurrent was the light-induced water oxidation reaction at the photosystem II complex. The thylakoid–MWNT composite electrode yielded a maximum current density of 68 μA cm−2 and a steady state current density of 38 μA cm−2, which are two orders of magnitude larger than previously reported for similar systems. The high electrochemical activity of the thylakoid–MWNT composites has significant implications for both photosynthetic energy conversion and photofuel production applications. A fuel cell type photosynthetic electrochemical cell developed using a thylakoid–MWNT composite anode and laccase cathode produced a maximum power density of 5.3 μW cm−2, comparable to that of enzymatic fuel cells. The carbon based nanostructured electrode has the potential to serve as an excellent immobilization support for photosynthetic electrochemistry based on the molecular tethering approach as demonstrated in this work.

High photo-electrochemical activity of thylakoid–carbon nanotube composites for photosynthetic energy conversion

ZIF-67 derived hollow cobalt sulfide as superior adsorbent for effective adsorption removal of ciprofloxacin antibiotics

Acetaminophen is a widely used drug worldwide and is frequently detected in water and wastewater as a high-priority trace pollutant. This study investigated the applicability of the adsorption processes using a composite of magnetic chitosan and multi-walled carbon nanotubes (MCS@MWCNTs) as an adsorbent in the treatment of acetaminophen. The model was well fitted to the actual data, and the correlation coefficients of R2 and adjusted R2 were 0.9270 and 0.8885, respectively. The maximum ACT removal efficiency of 98.1% was achieved at ACT concentration of 45 mg L-1, pH of 6.5, MCS@MWCNTs dosage of 400 mg L-1, and the reaction time of 23 min. The result shows that BET specific surface area of 640 m2 g-1. The adsorption isotherms were well fitted with the Langmuir Model (R2 =0.9961), depicting the formation of monolayer adsorbate onto the surface of MCS@MWCNTs. The maximum monolayer adsorption capacity of 256.4 mg g-1 was observed for MCS@MWCNTs. The pseudo-second-order kinetic model well depicted the kinetics of ACT adsorption on MCS@MWCNTs (R2=0.9972). Desorption studies showed that the desorption process is favored at high pH under Alkaline conditions. The results demonstrate that the MCS@MWCNTs is an efficient, durable, and sustainable adsorbent in water purification treatment.

Application of experimental design methodology to optimize acetaminophen removal from aqueous environment by magnetic chitosan@multi-walled carbon nanotube composite: Isotherm, kinetic, and regeneration studies

Response surface modeling of ceftriaxone removal from hospital wastewater

Introduction: Acetamiprid (AP) is one of the most widely used pesticides in the neonicotinoid class. AP residues in the environment have received considerable due to their potential toxicity to humans. Therefore, it is important to remove AP from the aqueous solution. 
Materials and Methods: In the current study, response surface methodology (RSM) was used as an efficient approach to optimize the removal of AP using the electro-Fenton (EF) process. The effects of the main variables, including reaction time, AP concentration, current density, and H2O2 dosage were investigated and optimized. ANOVA technique was also used to identify the Fisher’s value (F-value) and P-value of the model. 
Results: The predicted AP removal efficiency by the model was in good agreement with the obtained experimental results with correlation regression of 0.9885. The ANOVA test proved that the developed quadratic model was significant with very low P-values less than 0.05, the high F-value of 240.1, and regression coefficients close to 1 at a 95% confidence level. The optimum condition for AP removal efficiency of 99.02% was attained at the reaction time of 12 min, AP concentration of 3.5 mg L-1, the current density of 12 mA cm-2, and H2O2 dosage of 86 µL. 
Conclusion: RSM was employed as a suitable method to optimize the operating condition and maximize the AP removal. Herein, the EF process as an eco-friendly electrochemical advanced oxidation process (EAOP) successfully applied to remove AP from the water and wastewater.

Electrochemical Oxidation Approach towards the Treatment of Acetamiprid Pesticide from Polluted Water

Introduction: Perchloroethylene (PCE) is one of the most well-known chlorinated organic compounds recently detected in aqueous environments. The presence of PCE in aquatic ecosystems has caused many health problems and environmental challenges. Therefore, its removal and treatment from aqueous environments are essential. 
Materials and Methods: The electro-Fenton (EF) process was carried out in a cylindrical reactor containing 250 mL contaminated water with PCE. The effects of parameters, including solution pH (3-12), current density (2-10 mA cm-2), H2O2 concentration (20-70 µL H2O2 per 250 mL sample.), PCE concentration (5-50 mg L-1), and electrolysis time (1-15 min) on PCE degradation were investigated. The kinetics and radical’s scavenger of the EF process were examined to detect the exact mechanism of PCE degradation. 
Results: The degradation of the PCE of 98.1% was obtained in the optimum condition, including solution pH of 5, the current density of 8 mA cm-2, H2O2 concentration of 50 µL per 250 mL sample, PCE concentration of 15 mg L-1, and electrolysis time of 10 min. The kinetics studies of the EF process indicated that the obtained results were in satisfactory agreement with the first-order model (R2 = 0.9858, Kapp = 0.2822). Also, the addition of ethanol and tertiary butanol caused an inhibiting effect. 
Conclusion: The EF process was effectively applied to degrade PCE from polluted water as an efficient technique.  The obtained results indicated that the generation of •OH throughout the EF process was the key mechanism that controlled the EF process.

Degradation of High-Concentration of Perchloroethylene from Aqueous Solution Using Electro-Fenton Process

Background: Diazinon is one of the most important pesticides extremely used in agriculture. Since these compounds are resistant to biodegradation, the arrival of these compounds to water resources has become a serious environmental problem. Therefore, in the current work, the removal of diazinon from groundwater was investigated using advanced oxidation processes electro Fenton. Methods: the current work was conducted in lab scale. The effect of operating parameters such as initial concentration of diazinon (1-30 mg.L-1), pH solution(3-9), current density (1-10 mA.cm-2), reaction time (3-30 min), and dosage of H2O2 (20-100 mL.L-1) were investigated. Response surface methodology (RSM) was used to optimize the parameters and suggested model was analyzed using ANOVA. Results: On the optimum condition including initial diazinon concentration of 6.88 mg.L-1, pH solution of 3, the reaction time of 10 min, the current density of 8.18 mA.cm-2, and dosage H2O2 of 83.78 mL.L-1 removal efficiency of diazinon was found to be 98.5 . Electrical energy consumption (EEC) was found to be 0.524 kWh.m-3. Moreover, the concentration of diazinon in groundwater was found to be 0.934p0.053 mg.L-1. Conclusion: According to the obtained results, electro Fenton process was found to be an efficient technique for successful removal of diazinon and other resistant ungradable organic compound from water sources. n

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Saeid Ahmadzadeh

Papers

Application of experimental design methodology to optimize acetaminophen removal from aqueous environment by magnetic chitosan@multi-walled carbon nanotube composite: Isotherm, kinetic, and regeneration studies

Response surface modeling of ceftriaxone removal from hospital wastewater

Electrochemical Oxidation Approach towards the Treatment of Acetamiprid Pesticide from Polluted Water

Degradation of High-Concentration of Perchloroethylene from Aqueous Solution Using Electro-Fenton Process

Modeling of Electro Fenton Process for Removal of Diazinon from Groundwater Using Response Surface Methodology