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In this report recycled LiFePO4 (LFP) from exhaust batteries was utilized to form B@C3N4/LiFePO4/CuFe2O4 (BLC) nano-junction as a visible active photocatalyst. The junction synthesized by two routes: Using as extracted LFP and forming LFP by extracted FePO4 and Li2CO3 via in-situ deposition method. The two ternary junctions BLC and BLC (E) (utilizing as extracted LFP) were utilized for visible and solar powered degradation of beta-blocker drug Atenolol (ATL). Varying the loading of CuFe2O4 (CF) which possesses lowest band gap, BLC (10%), BLC-3 (30%), BLC-5 (50%) and BLC-E (30% CF and as extracted LFP) were produced with BLC-3 exhibiting remarkable activity. The optical band gaps of BLC-3 (2.40 eV) and BLC (E) (2.46 eV) and photocurrent responses reveal high visible absorption and highly diminished recombination. 99.5% and 85.3% of ATL (20 mg L-1) could be degraded by BLC-3 and BLC (E) (0.3 g L-1) respectively in 60 min of exposure to Xe lamp and retaining of high activity in natural sunlight. Band-junction analysis, effect of scavengers and effect on teraphthalic acid and nitroblue tetrazolium reveal O2- and OH radicals as active species and mineralization was confirmed by liquid chromatography-mass spectrometer (LC-MS). Cyto-toxicity studies on human peripheral blood cells and effect on growth of Pseudomonas aeruginosa confirm the complete mineralization. The BLC photocatalyst is a promising multi-functional catalyst utilizing LFP (rarely used as photocatalyst) for treatment of pharmaceutical waste water and other environmental applications.

An inclusive study towards the stereospecific synthesis of novel cis-3-monosubstituted-β-lactams from cis-3-functionalized 3-phenylsulfonyl/sulfinyl-β-lactams is described. 3-Sulfinyl-β-lactams 5/5ʹ successfully furnished stereospecific cis-3-monosubstituted-β-lactams 6, however 3-sulfonyl-β-lactams 2 failed to give the desulfurized product 6ʹ. The final stereochemical and structural conformations of novel β-lactams were established by single crystal X-ray crystallographic study (5c). The cis configuration of the β-lactams 5/5ʹ and 6 was assigned in relevance to E and C4-H and C3-H and C4-H respectively.

Heterogeneous catalysis has great application potential in numerous industries and significant role in global economic development. The high speed of catalyzed reactions and guaranteeing high selectivity to the target products are the two important aspects in heterogeneous catalysis. In heterogeneous catalysis, widespread attention has been engrossed by bimetallic nanoparticles/metal organic framework (MOF) materials. These materials are used in diverse incipient application areas such as electrochemical energy storage batteries, supercapacitors and have prospective applications in gas separation, sensing, catalysis, and energy storage and conversion. The bimetallic MOF catalysts exhibited enhanced catalytic activity compared with that of mono metal catalyst. The simplicity of synthesis of bimetallic MOFs is considered a great advantage, and the bimetallic MOFs are recognized as new class of active materials for energy conversion and storage. In this article, an attempt has been made to thoroughly summarize the development of bimetallic MOFs as well as their useful fabrication approaches and applications in numerous heterogeneous catalytic reactions.

Inspired by waste to energy production, we report construction of dual Z-scheme advanced photocatalyst g-C3N4/Bi4Ti3O12/Bi4O5I2 heterojunction for coupled photocatalytic H2 evolution and degradation of antibiotics with high efficiency. The optimal CTBT-30 i.e (40 %g-C3N4/Bi4Ti3O12)/30 % Bi4O5I2 photocatalyst exhibited an excellent rate of H2 production under visible light (56.2 mmol g−1 h−1) along with simultaneous 87.1 % ofloxacin (OFL) removal. The H2 production rate is manifolds higher than in ultrapure water, sulfadiazine, rhodamine B and higher in hole scavenging triethanolamine. The interfacial intimate coupling with well-matched energy bands, foster the charge separation with effective Z-scheme transfer facilitated by I3−/I− and Bi3+/Bi5+ and redox mediators. The scavenging of majority of holes for direct oxidation or via OH radical formation leaves photogenerated electrons (at CB of g-C3N4 and Bi4O5I2) free for H2 evolution from H2O. Such work is promising for designing high photo-absorbing heterojunction photocatalysts for dual functionalities of clean energy production and environmental detoxification.

An efficient and operationally simple strategy for the stereoselective synthesis of novel C-3 functionalized 3-sulfonyl-β-lactam heterocycles is described. The C-3 functionalized 3-phenyl/benzylsulfonyl-β-lactams 3/3′, 5/5′ has been synthesized via Michael addition using different Michael acceptors on trans-3-phenyl/benzylsulfonyl-β-lactams 2(a–f) using K2CO3 as a base and acetonitrile/DMF as solvents. The reaction furnished exclusively cis-β-lactam adducts 3(a–r) using sterically less hindered Michael acceptors. Further, the effect of steric bulk and chiralilty of Michael acceptors was explored to achieve target C-3 functionalized β-lactams 3(s-u)/3′(s-u) and 5(a–c)/5′(a–c). The structural and stereochemical analysis of novel β-lactams were carried out using FT-IR, NMR (1H, 13C, 1H-1H COSY, 1H-13C COSY and 13C DEPT-135), elemental analysis (CHNS), mass spectrometry (EIMS and LCMS) in representative cases and single crystal X-ray crystallographic studies (3e). The cis or trans configuration of the Michael acceptor (E) at C-3 was assigned with respect to C4-H.

The efficient diastereoselective synthesis of 3-acetoxy/methoxy/phthalimido-β-lactams 2/2′ , 3/3′ and 4/4′ respectively was performed using chiral imines 1 obtained from chiral amines. Factors (solvent, temperature, substituent, steric bulk) influencing the stereoselectivity and the diastereomeric ratio were also studied in detail. The diastereoselectivity of the two isomers was determined from the ratio of integral values of doublets of C3–H and C4–H and from the integral values of H in –C H (Me/Et)Ph/Np of the two diastereomers. Representative pairs of cis -diastereomers were separated by efficient column chromatography.

Pharmaceutical effluents in water bodies pose hazards to the ecosystem because of their potent biological toxicity. Focusing on the removal of such toxic complicated pharmaceutical residues, an innovative LaTiO2N/g-C3N4@Fe3O4 heterojunction photocatalyst was assembled by a simplistic route for visible and solar light degradation of anti-inflammatory drug indomethacin (IDM). The LCF-20 catalyst (with LaTiO2N:g-C3N4 -0.2:1) shows excellent performance for visible light photodegradation of IDM, as evidenced by 97.3 % removal in just 45 min exposure which is about 13 times faster than bare g-C3N4. 83.4 % of total organic carbon removal was achieved by LVF-20 under visible light. Also, with natural sunlight, nearly 80 % of IDM was removed in 90 min irradiation. The heterojunction’s extensive intimate interfacial interactions amid LaTiO2N and g-C3N4 reduce the shortcomings of the two for a better photo-activity. The high visible activity, diminished recombination, high charge transfer is attributed to effective Z-scheme transfer facilitated by Fe3O4 nanoparticles. Scavenging experiments prove the importance of superoxide radicals as the dominant species responsible for photodegradation reaction. By mass spectrometry and total organic carbon analysis, a reaction mechanism was also reasonably proposed. The photocatalytic mechanism was discussed in light of conventional and Z-scheme transfer for better insight. The catalyst is stable, recyclable and magnetically separable. This investigation offers a new perspective in the rational design and manufacture of organic-inorganic nitrides based magnetically recoverable heterojunctions as LaTiO2N/g-C3N4@Fe3O4. Such heterojunctions present a new class of robust hierarchical photocatalytic materials which are capable of remediation of pharmaceutical residues under practical conditions.

Graphitic carbon nitride based photocatalytic materials have proved to be one of most promising candidates for hazardous pollutant removal and clean energy production. Structural modification and engineering of various materials based on g-C3N4 have been attempted to achieve solar energy harvesting, slow charge transfer and efficiency. Here we report synthesis of all metal free self-assembled carbon quantum dots and reduced graphene oxide layers modified S@g-C3N4/B@g-C3N4 (CRSB) photocatalyst for visible and solar degradation of chloramphenicol (CMP) (10 mg L−1). Differently doped g-C3N4 with different band structure forms a junction which grows into an effective Z-scheme photocatalyst. Extended visible absorption is achieved with optimized modification by reduced graphene oxide (RGO) and carbon quantum dots. The optical response, band structure and charge separation efficiency were tested by optical absorption, electrochemical impedance, Mott-Schottky plots and photo-luminescence. CQDs convert a typical type-II mechanism into effective Z-scheme transfer. For the best sample CRSB 99.1% CMP was photo-degraded in 90 min exposure to visible light and retention of high activity in natural solar light (92.4% in 120 min). A stable heterojunction has been attempted to design using boron doped g-C3N4 and sulphur doped g-C3N4 with different band positions via ratio optimization with enhanced charge transfer. The degradation rate for CRSB (0.0810 min−1) is 10 times than bare g-C3N4 (0.00802 min−1). The optimized combination of carbon quantum dots and RGO with intimate interfacial contact for charge flow & reduced recombination, better adsorption of pollutant, high visible absorption and production of reactive oxygen species. The effect of pH, electrolytes and water matrix was studied for CMP degradation. The mechanism of degradation and mineralization was confirmed by liquid chromatography-mass spectrometry (LC-MS) analysis, scavenging experiments and electron spin resonance. It was observed that the chances of •O2– and •OH radicals increased on the formation of the junction as compared to individual doped and bare carbon nitride. The mineralization was ensured by high total organic removal and cyto-toxicity studies of treated water sample onto human peripheral blood (PBL) cells with high cell viability equivalent to untreated cells. This experiment supports the competence of optimally designed metal free and environmentally friendly cost-effective catalysts with higher photocatalytic efficiency for removal of hazardous pollutants.

A novel design of all optical binary to gray code converter is proposed and described. Gray code is a cyclic code, in which predecessor and successor codes have one bit change. So these codes are suitable for error detection in the optical communication. This device consists of Mach-Zehnder interferometer as switching element, having the ability to switch the light from one port to other port at ultra-fast rate. The performance parameters like extension ratio and insertion ratio are computed and obtained as 20.59 dB and 0.951 dB respectively. Further the study is verified using finite difference time division method. The results are also verified mathematically and with MATLAB.

The voluminous anthropogenic activities and non-regulated discharge of emerging pharmaceutical pollutants have led to deterioration of water quality characteristics and shortage of potable water. One of most ubiquitous problems is that the pharmaceutical pollutants are slowly developing resistance in pathogens, which increases the risks manifold. Conventional water treatment methods and technologies have been known to be inadequate for elimination of recalcitrant and emerging pollutants. Advanced oxidation processes have been exploited to the most for mineralizing the pollutants with some limitations especially toxic metal based catalysts and secondary pollution. However Fenton-based systems are considered to be safer as they utilize non-toxic chemicals. Homogeneous Fenton processes suffer from limitations as limited pH operational range, generation of Fe containing sludge etc. have shifted focus to heterogeneous systems. This review focusses on removal of pharmaceutical pollutants by homogeneous and heterogeneous Fenton, electro-Fenton, sono-Fenton, photo-Fenton and photo-electro-Fenton processes using nano-catalysts. Various types of new pharmaceutical pollutants, their emergence, characteristics and toxicity have been discussed to have an insight into quantity and variety. New Fenton-like catalysts have been designed and used for degradation of pollutants and high mineralization is also achieved in a wide pH-range. In addition Fenton catalysts capable of showing high mineralization using solar light have been prepared by various methods with and without iron based materials. In addition in this review we have also focused on complexities related to removal of pharmaceutical effluents and how they are addressed by Fenton systems. The review aims to assist researchers and engineers to gain fundamental understandings and critical view of Fenton process and its optimization processes, and hopefully with the knowledge it could bring new opportunities for the optimization and future development of Fenton process. The key advances in Fenton catalysts are innovations in design of ligands, junction designing for effective radical generation, reaction engineering, hydro-dynamical effects and complete mineralization. The combinations and coupling of biological oxidation, semiconductor photocatalysis with Fenton process for high performance pharmaceutical pollutants removal in pilot-scale experiments have been discussed and evaluated.

There is increasing empirical evidence that the climate in Nepal is changing and will continue to do so for the foreseeable future, with substantial impacts on the long-established ways of life of the local people. The development of responsive actions, or climate change adaptation, hinges on understanding how people make sense of changes in their local climate and how they interpret associated risks and opportunities. Based on a qualitative case study with 30 tourism stakeholder participants in the Annapurna Region of Lower Mustang, Nepal, this research explored people’s understanding of climate change and their perceptions of different levels of impact. The range of perceived impacts is discussed against the background of multiple livelihoods and diverse cultural interpretations. Participants, while not always scientifically ‘accurate’ in their assessments, displayed a high level of engagement with, and understanding of their local environment and climate. The results of this study provide further testimony to the value of local knowledge on relevant climate parameters and impacts, and the role it could play in enhancing the usefulness of macro-level climate projections, as well as local-level climate change adaptation initiatives.

Capillary enzyme immunoassay with flow-injection analysis for digoxin using the sequential saturation technique has been developed. Glass capillary tubes (10 cm × 0.53 mm i.d.) with immobilized digoxin antibody were used as the immunoassay reactor. The product of enzymatic reaction. 4-aminophenol, was detected amperometrically. The digoxin and the labeled digoxin binding reaction with the immobilized digoxin antibody were completed in 2 and 10 min, respectively. Digoxin was determined in a 20-μl sample with a detection limit of 10 pg ml−1 (200 fg or 260 attomoles) and a 3 orders of magnitude range.