Converting Ag3PO4/CdS/Fe doped C3N4 based dual Z-scheme photocatalyst into photo- Fenton system for efficient photocatalytic phenol removal

Aftab Aslam Parwaz Khan,Pardeep Singh,Pankaj Raizada,Abdullah M. Asiri 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.98 No.-

In this work, a dual Z-scheme Ag3PO4/CdS/Fe-g-C3N4 (AP/CdS/FeCN) photocatalyst was prepared byprecipitation- deposition method. AP/CdS/FeCN photocatalyst was converted into the heterogenousphoto-Fenton system with the addition of H2O2. The synergistic coupling between AP/CdS/FeCN andH2O2 resulted in enhanced for phenol degradation, with a rate constant of constant 6.2 10 4 s-1, which is1.31 and 1.61 times than that of AP/CdS/FeCN and Fe2O3/H2O2. The enhancement in photodegradationwas attributed to (i) more regeneration of Fe2+ ions, (ii) enhanced visible light absorption, (iii) elevatedredox potential due to more hydroxyl radical’s formation, and (iv) low Fe leaching in the reactionsolution. As indicated by EIS, PL, and trapping experiments, photoinduced CB electrons of g-C3N4 and CdSwere transferred entirely to Fe3+ to regenerate Fe2+ ions to accelerate the Fenton cycle. In comparison tothe conventional Fe2O3/H2O2 Fenton process, Fe ion leaching in AP/CdS/FeCN/H2O2 catalytic system wasalmost negligible. It confirmed strong chemical interaction of Fe3+ with g-C3N4. AP/CdS/FeCN/H2O2displayed significant catalytic efficacy andfirmness forfive successive catalytic cycles. Moreover, the AP/CdS/FeCN/H2O2 nanocomposite exhibited substantial mineralization perfomance for other phenolicpollutants. The results demonstrate that AP/CdS/FeCN/H2O2 catalytic system has the potential for waterpurification.

Mechanistic investigation of the oxidation of Cefuroxime by hexacyanoferrate(III) in alkaline conditions

Aftab Aslam Parwaz Khan,Abdullah M. Asiri,Anish Khan,Naved Azum,Malik Abdul Rub,Mohammed M. Rahman,Sher Bahadar Khan,K. S. Siddiqi,Khalid A. Alamry 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

The reactions of Cefuroxime (CFA) by hexacyanoferrate (III) (HCF(III)) in alkaline medium at a constant ionic strength has been studied spectrophotometrically. It is a first order reaction, but fractional order in both CFA and alkali. Decrease in dielectric constant of the medium decreases the rate of reaction. The effect of added products and ionic strength has also been investigated. A mechanism involving free radicals is proposed. In a composite equilibrium step, CFA binds to HCF(III) to form a complex that subsequently decomposes to the products. The main two products were separated and identified by column chromatography, TLC and FT-IR. There is good agreement between the observed and calculated rate constants under different experimental conditions. The reaction was studied at different temperatures and activation parameters were computed with respect to the slow step of the proposed mechanism.

Catalyst usage of micro concentration of Mn(II) for the oxidation of biotin by peroxomonosulphate in aqueous medium:A mechanistic approach

Aftab Aslam Parwaz Khan,Anish Khan,Abdullah M. Asiri,Malik Abdul Rub 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5

In this paper provides the mechanistic investigation of Mn(II)-catalyzed oxidative of biotin (BTN) has been studied by peroxomonosulphate (PMS) in alkaline medium at 293–308 K with a constant ionic strength. Such studies are much helpful in gaining an insight into the interaction of metal ions through the study of the mechanistic pathway of biotin in redox reactions. The stoichiometry of the reaction is 1:1 in the presence of catalyst. The reaction shows polymerization in the presence of acrylonitrile under the experimental conditions employed. Influence of dielectric constant and ionic strength of the medium on the reaction rate have been done. Manganese peroxide was proposed as the intermediate to explain the experimental observations. Temperature effect is noticeable in all these reactions and activation parameters have been determined. The effect of temperature was evaluated by Arrhenius equation and transition state theory, a mechanism was proposed based on the observation of the experimental results. It involves the formation of an activated complex, which decomposes to give the product. It is identified with the help of FTIR and TLC.

Spectrophotometric Investigation of Oxidation of Cefpodoxime Proxetil by Permanganate in Alkaline Medium: A Kinetic Study

Khan, Aftab Aslam Parwaz,Mohd, Ayaz,Bano, Shaista,Siddiqi, K. S. Korean Chemical Society 2009 대한화학회지 Vol.53 No.6

A Kinetics pathway of oxidation of Cefpodoxime Proxetil by permanganate in alkaline medium at a constant ionic strength has been studied spectrophotometrically. The reaction showed first order kinetics in permanganate ion concentration and an order less than unity in cefpodoxime acid and alkali concentrations. Increasing ionic strength of the medium increase the rate. The oxidation reaction proceeds via an alkali-permanganate species which forms a complex with cefpodoxime acid. The latter decomposes slowly, followed by a fast reaction between a free radical of cefpodoxime acid and another molecule of permanganate to give the products. Investigations of the reaction at different temperatures allowed the determination of activation parameters with respect to the slow step of proposed mechanism and fallows first order kinetics. The proposed mechanism and the derived rate laws are consistent with the observed kinetics. 일정한 이온 세기의 알칼리 용액에서 과망간산에 의한 프포독심 프록세틸(Cefpodoxime Proxetil) 의 산화의 속도론적 경로가 분광광도법적으로 연구되었다. 그 반응은 과망간산 이온 농도에서 일차 속도론적으로 나타났으며, 프포독심 산과 알칼리 농도에서 단일 이하의 차수를 나타내었다. 용매의 이온 세기가 증가함에 따라 속도도 증가하였다. 산화 반응은 프포독심 산과 함께 복합체를 형성하는 알칼리-과망간산 종들을 통하여 진행된다. 반응물을 만들기 위해서 프포독심 산의 자유 라디칼과 과망간산의 다른 분자 사이의 빠른 반응에 이어서 다음 분해가 천천히 진행된다. 다양한 온도에서 반응의 조사는 제안하는 메커니즘의 느린 단계를 고려한 활성화 변수들의 결정할 수 있게 하고 일차 속도론을 따른다. 제안하는 메커니즘과 유도된 속도 법칙들은 관찰된 속도들과 일치하였다.

Applied poly(2-methoxy aniline) Sn(II)silicate carbon nanotubes composite: Synthesis, characterization, structure–property relationships and applications

Anish Khan,Aftab Aslam Parwaz Khan,Abdullah M. Asiri,Malik Abdul Rub,Naved Azum,Sher Bahadar Khan,Hadi M. Marwani 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

A new class hybrid poly(2-methoxy aniline) Sn(II)silicate carbon nanotubes composite was synthesized by sol–gel method. The physico-chemical characterization was carried out by Scanning Electron micrograph, X-ray Diffraction, Fourier Transform Infrared, Ultraviolet–Visible Spectroscopy and simultaneous Thermo Gravimetric Analysis. The ion-exchange studies were also carried out to understand the ion-exchange capabilities. The dc electrical conductivity studies reviles its highly conducting nature in the range of 2–3-2 S cm-1. On the basis of distribution studies it was found highly selective for Hg2+. Due to selectivity of the composite, ion selective membrane was prepared and employed it as an indicator electrode in potentiometric titrations.

Current status on designing of dual Z-scheme photocatalysts for energy and environmental applications

Rohit Kumar,Anita Sudhaik,Aftab Aslam Parwaz Khan,Pankaj Raizada,Abdullah M. Asiri,Satyabrata Mohapatra,Sourbh Thakur,Vijay Kumar Thakur,Pardeep Singh 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.106 No.-

Growing pollution and high energy demand are some of the major issues against humans. Waterpollution is one of the main problems created due to industrial waste and irresponsible human activities. Nowadays, photocatalysis is rising as an efficient alternative to overcome the energy requirement andwater purification, as it can use solar light as a source of energy. Due to some limitations of photocatalysts,such as photocarriers recombination, low surface area, and limited light absorption, modificationssuch as defect modifications, heterojunction can be employed. Out of all, Z-scheme heterojunction is aproficient way to overwhelm the limitation of pristine photocatalysts. To enhance the activity of Zschemephotocatalyst, even more, a dual Z-scheme photocatalytic scheme has been developed in whichtwo Z-scheme based charge transfer occur simultaneously on a ternary photocatalyst. In this review, wehave discussed the different types of dual Z-schemes along with their application in water purificationand finally, we have discussed the future prospects for further research.

Amphiphilic antidepressant drug amitriptyline hydrochloride under the influence of ionic and nonionic hydrotropes; micellization and phase separation

Malik Abdul Rub,Abdullah M. Asiri,Naved Azum,Anish Khan,Aftab Aslam Parwaz Khan,Sher Bahadar Khan,Mohammed M. Rahman,Kabir-ud-Din 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.6

Herein we report the micellization and cloud point of an amitriptyline hydrochloride (AMT) under the influence of cationic, anionic and nonionic hydrotropes. Anionic hydrotropes were employed to know the micellar and surface behaviors, besides studying the clouding behavior of AMT drug with cationic,anionic and nonionic hydrotropes. Tensiometric study has been performed and the properties studied include the critical micelle concentration (cmc), maximum surface excess at the air/water interface (Gmax), the minimum area per of amphiphilic molecule at air/water interface (Amin), and the different thermodynamic parameters, besides clouding phenomenon. Interaction parameters of micelles (bm) and monolayer (bs) indicate that drug-hydrotrope systems show better interaction at the interface than in micelles.

Interaction of CFP with Metal ions: Complex Formation of CFP with Metal ion by Absorption and Fluorescence Spectrophotometery

Siddiqi, K.S.,Mohd, Ayaz,Khan, Aftab Aslam Parwaz,Bano, Shaista Korean Chemical Society 2009 대한화학회지 Vol.53 No.2

산성 용액에서 $Ca^{2+},\;Mg^{2+},\;Mn^{2+},\;Fe^{3+},\;Co^{2+},\;Ni^{2+},\;Cu^{2+}$ 및 $Zn^{2+}$와 Cefpodoxime proxetil (CFP)의 상 호작용을 분광학적으로 조사한 결과 1:1 착물이 형성됨을 알 수 있다. 순수한 약품의 흡수스펙트럼은 270과 345 nm에서 두 개의 현저한 봉오리를 보였다. 여러 pH에서 스펙트럼은 두 개의 isosbestic 점(305 과 330 nm)을 나타내었다. 이는 용액상에서 약품의 쯔비터 이온이 존재함을 의미한다. 다른 농도의 금 속이온에서 CFP의 형광방출 스펙트럼은 chelating enhancement fluorescence(CHEF)효과에 의해 형광강 도가 증가함을 알 수 있었다. 착체의 화학량론은 Job’'s 와 Benesi-Hildebrand 방법에 의해 결정되었다. 착 체의 안정도는 다음 순서와 같다. $Ca^{2+}\;<\;Mg^{2+}\;<\;Co^{2+}\;<\;Ni^{2+}\;<\;Zn^{2+}\;<\;Mn^{2+}\;<\;Cu^{2+}\;<\;Fe^{3+}$. Spectrophotometric investigation of the interaction of Cefpodoxime proxetil (CFP) with $Ca^{2+},\;Mg^{2+},\;Mn^{2+},\;Fe^{3+},\;Co^{2+},\;Ni^{2+},\;Cu^{2+}$ and $Zn^{2+}$ in acidic medium showed the formation of 1:1 complex. The absorption spectrum of pure drug exhibits two prominent peaks at 270 and 345 nm. Its spectra scanned at several pH exhibited two isosbestic points (305 and 330 nm) indicating the presence of zwitterionic condition of drug in solution phase. The fluorescence emission spectra of CFP in presence of different concentrations of metal ions showed enhancement in fluorescence intensity which is ascribed to chelating enhancement fluorescence effect (CHEF). The stoichiometry of the complexes was determined by Job’s and Benesi-Hildebrand method. The stability of the complexes follow the order $Ca^{2+}\;<\;Mg^{2+}\;<\;Co^{2+}\;<\;Ni^{2+}\;<\;Zn^{2+}\;<\;Mn^{2+}\;<\;Cu^{2+}\;<\;Fe^{3+}$.

An overview of SnO2 based Z scheme heterojuctions: Fabrication, mechanism and advanced photocatalytic applications

Akshay Chawla,Anita Sudhaik,Pankaj Raizada,Aftab Aslam Parwaz Khan,Archana Singh,Quyet Van Le,Van Huy Nguyen,Adem Sreedhar,Saad M. Alshehri,Abdullah M. Asiri,Pardeep Singh 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.116 No.-

Not just people, but all living species, desire a clean and green environment to live a happy and healthylife. However, in our ever-increasingly congested world, it is quite challenging. Excessive deforestation,factory smoke, various chemical compounds, agricultural chemicals, etc. all pollute our environmentseverely. Some of its adverse consequences include water contamination and a shortage of energy supplies. In recent times, photocatalysts have sparked tremendous attention as a means of addressing energydemands as well as environmental challenges (water pollution). For this, SnO2 and SnO2 based photocatalystshave gained a great attention due to its good photocatalytic ability. In the same way, SnO2-based Zschemephotocatalysts has extended significant interest to address these concerns due to its strong photocatalyticcharacteristics, energy savings, eco-friendliness, and lack of adverse health effects. Though, thephotocatalytic effectiveness of conventional SnO2 semiconductors, with their shortcomings, falls wellshort of the real requirements. The current review emphasizes on admirable properties and several synthesisprocesses of SnO2 which make it an ideal photocatalyst. This study also stresses the fundamentalshortcomings of SnO2 that restrict its utilization. The central section of this review is concentrated onSnO2-based Z-scheme photocatalysts and most recent significant research modification of Z-schemeSnO2-based photocatalysts. The photocatalytic applications of Z-scheme SnO2-based photocatalysts forpollutants removal, energy conversion, and water splitting are also summarized. In conclusion, we haveaddressed the challenges and future exploration of SnO2-based photocatalysts with a Z-scheme heterojunctiontype for pollutant degradation and energy conversion.

Magnetic molecularly imprinted polymer photocatalysts: synthesis, applications and future perspective

Komal Poonia,Pankaj Raizada,Archana Singh,Narinder Verma,Tansir Ahamad,Saad M. Alshehri,Aftab Aslam Parwaz Khan,Pardeep Singh,Chaudhery Mustansar Hussain 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.113 No.-

Effective degradation of low-concentration pollutants is a critical challenge during the water purificationprocess. The use of different chemicals can leave residue in samples that can impose potential ecotoxicologicaland adverse impacts on human health. Presently, Magnetic molecularly imprinted polymers(MMIPs) have attracted much attention as the research material comprises a non-magnetic polymerand magnetic material for selective binding for target molecule and recoverability of catalyst via magnetism,respectively. This review explains the synergistic effect of adsorption with photocatalysis tounderstand their recognition mechanism and the possible interaction between the target molecule andMIPs. Then their common imprinting polymerization processes i.e., free radical polymerization andnon-free radical polymerization are briefly discussed with their respective advantages and disadvantages. In addition, this review highlights the photocatalytic degradation mechanism of photocatalyst cumadsorbent is critically discussed by comparing it with non-imprinted polymers. Finally, the applicationsof MMIPs in the removal or degradation of refractory pollutants, sensing, and recognition have alsobeen delineated. This paper summarises progressive future challenges of the technology that need tobe exploited for the preparation of the targeted catalyst.