All-solid-state Z-scheme ZnFe-LDH/rGO/g-C3N5 heterojunction for enhanced sonophotocatalytic degradation of ciprofloxacin: Performance and mechanistic insights.

The fabrication of all-solid-state Z-scheme sonophotocatalysts is vital for improving the transfer rate of photogenerated electrons to remove antibiotics present in wastewater. Herein, a novel indirect Z-scheme ZnFe-layered double hydroxide (LDH)/reduced graphene oxide (rGO)/graphitic carbon nitride (g-C3N5) heterojunction was synthesized using a simple strategy. The ZnFe-LDH/rGO/g-C3N5 (ZF@rGCN) ternary composites were systematically characterized using different techniques. Results revealed that the 15%ZF@rGCN catalyst achieved a ciprofloxacin (CIP) degradation efficiency of 95% via the synergistic effect of sonocatalysis and photocatalysis. The improved sonophotocatalytic performance of the ZF@rGCN heterojunction was attributed to an increase in the number of active sites, a Z-scheme charge-transfer channel in ZF@rGCN, and an extended visible light response range. The introduction of rGO further enhanced the charge-transfer rate and preserved the reductive and oxidative sites of the ZF@rGCN system, thereby affording additional reactive species to participate in CIP removal. In addition, owing to its unique properties, rGO possibly increased the absorption of incident light and served as an electronic bridge in the as-formed ZF@rGCN catalyst. Finally, the possible CIP degradation pathways and the sonophotocatalytic Z-scheme charge-migration route of ZF@rGCN were proposed. This study presents a new approach for fabricating highly efficient Z-scheme sonophotocatalysts for environmental remediation.

Noble metal nanoparticles (Mx = Ag, Au, Pd) decorated graphitic carbon nitride nanosheets for ultrafast catalytic reduction of anthropogenic pollutant, 4-nitrophenol.

We report an effective facile immobilization of noble nanoparticles (Mx = Ag, Au and Pd) assembled on g-C3N4 (g-CN) prepared via a simple ultra-sonication strategy. The Mx assembled g-CN nanocomposites were applied for the effective conversion of 4-nitrophenol (4-NP). As prepared nanocomposites were characterized by techniques of XRD, SEM-EDS, TEM, XPS, and FT-IR analysis to gain crystallographic structural, and morphological insights. The Pd@g-C3N4 (Pd@g-CN) nanocomposite exhibited best catalytic performance (kapp = 1.141 min-1) toward the conversion of 4-NP to 4-aminophenol (4-AP), almost 100% within 4 min using aqueous sodium borohydride (NaBH4). The higher catalytic efficiency of Pd@g-CN could be attributed to the surface electron density on the Pd and rapid electron transfer capacity. Interestingly, g-CN not only role as a stabilizer but also provided compatibility for noble metal deposition, which improves the chemical and morphological stability of noble metal nanoparticles. Different reaction parameters including concentrations of 4-NP, and catalyst amount were studied. These unique combinations make noble metal nanoparticles anchored g-CN nanosheets an ideal platform for catalysis applications and environmental remediation.

Nano Ag@bioactive microspheres from marine sponge Clathria frondifera: Fabrication, fortification, characterization, anticancer and antibacterial potential evaluation.

Bioresources are attaining much importance in the discovery of drugs and delivering agents. In particular, marine sponges are of great interest due to their metabolites production for the survival in risky environment. The incorporation of silver nanoparticles with marine sponge derived metabolites was reported for the first time. In this work, a facile material has been generated of great efficacy in solving environmental and health issues, as a recipe of silver and marine sponge Clathria frondifera, named as Ag Fortified Sponge spheres (AFS). AFS spheres were successfully synthesized after method optimization, using the various extracts of marine sponge Clathria frondifera as effective reducing agent in Ag (I) to Ag (0) reduction. Bioactive material from marine sponge and AgNP from the reduction of AgNO3 solution stablishing one another and thus AFS spheres were attaining long lifetime along with enhanced antimicrobial activity. The characterization of synthesized AFS and other AgNPs (1-4) has done using FT-IR, PXRD, FESEM, TEM, and UV-vis data. The presence of functional groups such as, Ag-O, and Ag-C stretching bonds in the AFS compounds indicated that it is composed of silver oxides and organo-silver, respectively. The synthesized Ag NPs were found to be spherical like structure with an average size of ∼20 nm. The cytotoxic response of AFS was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and morphological changes. AFS are exact spherical, micro sized and effective in inhibiting the growth of both gram positive and gram-negative bacteria. Anticancer studies were also carried out and ensued with excellent activity in the HELA cells with potential application in the medical industry.

Adsorptive and photocatalytic performance of cobalt-doped ZnTiO3/Ti3C2Tx MXene nanohybrids towards tetracycline: Kinetics and mechanistic insight.

Tetracycline (TC) antibiotics are widely used in animal husbandry and can cause environmental risk due to its high ecological toxicity and persistence. In this study, cobalt doped/ZnTiO3 (ZTO)/Ti3C2Tx MXene (ZCxTM, x indicates wt% of Co loading) was synthesized and explored to remove TC by adsorption and photocatalysis under visible light irradiation. The as-prepared ZC5TM was characterized using various analytical techniques, and key operating parameters such as solution pH, background ions, and temperature were systematically investigated. Interestingly, ZC5TM (14.9 mg/g) showed excellent adsorption capacity for TC, which was higher than activated carbon (7.7 mg/g), ZTO (4.9 mg/g), ZC3T (5.2 mg/g), ZC5T (5.3 mg/g), MXene (12.1 mg/g), ZTOM (12.5 mg/g), and ZC3TM (12.9 mg/g). The pseudo-second-order kinetics and Langmuir isotherm models well explained the effect of contact time and initial concentrations on the adsorption of TC. The adsorption process was primarily through the electrostatic attraction, surface complexation, and hydrogen bonding. In addition, MXene and Co doped on ZTO served as co-catalyst and reduced recombination rate of photo-generated e--h+ pairs by the intimate interface of its heterojunction. Thus, ZC5TM was highly effective for the photocatalytic degradation of residual TC after adsorption by showing 18% TC degradation rate, compared to 8% and 9% degradation rate for ZTO and MXene, respectively. There results finally support the feasible use of ZC5TM as efficient adsorbent and photocatalyst in removal of TC in wastewater.

Application of perovskite oxides and their composites for degrading organic pollutants from wastewater using advanced oxidation processes: Review of the recent progress.

In the recent years, perovskite oxides are gaining an increasing amount of attention owing to their unique traits such as tunable electronic structures, flexible composition, and eco-friendly properties. In contrast, their catalytic performance is not satisfactory, which hinders real wastewater remediation. To overcome this shortcoming, various strategies are developed to design new perovskite oxide-based materials to enhance their catalytic activities in advanced oxidation process (AOPs). This review article is to provide overview of basic principle and different methods of AOPs, while the strategies to design novel perovskite oxide-based composites for enhancing the catalytic activities in AOPs have been highlighted. Moreover, the recent progress of their synthesis and applications in wastewater remediation (pertaining to the period 2016-2022) was described, and the related mechanisms were thoroughly discussed. This review article helps scientists to have a clear outlook on the selection and design of new effective perovskite oxide-based materials for the application of AOPs. At the end of the review, perspective on the challenges and future research directions are discussed.

Reduction of hexavalent chromium and degradation of tetracycline using a novel indium-doped Mn2O3 nanorod photocatalyst.

This study investigates the photocatalytic reduction of hexavalent chromium (Cr(VI)) and degradation of tetracycline (TC) via visible-light-active In-doped Mn2O3 photocatalysis. Mn2O3 photocatalysts loaded with different In doses are prepared using a simple hydrothermal method, and the results indicate the formation of Mn2O3 nanorod-like structures with good crystallinity. The most significant photocatalytic parameters, namely the catalyst and substrate concentrations, pH, and co-existing ions for the Cr(VI) reduction and TC degradation reactions are systematically examined. Result demonstrates that the Cr(VI) reduction and TC mineralization efficiencies of 52% and 40%, respectively are achieved at the optimum pH of 7, undoped Mn2O3 (10 mg/L), and Cr(VI) or TC concentration of 50 mg/L. However, these efficiencies are remarkably increased to 95% and 93%, respectively, when 10 mg/L of 5% In-doped Mn2O3 is used as the photocatalyst under the same reaction conditions. Moreover, the co-existing HCO3- anions and Ca2+ and Mg2+ divalent cations considerably deteriorate the performance of the In-doped photocatalysts compared with the SO42- and Cl- anions and Na+ and K+ monovalent cations. Liquid chromatography-mass spectrometry analysis reveals that the photodegradation of TC is mainly driven by the elimination of the -CH3 group followed by the subsequent cleavage of the primary -NHCH3 group.

A study of prevalence and correlates of nonadherence to immunosuppressive medications in renal transplant recipients of South Indian population and their impact on long-term graft function.

Nonadherence to immunosuppressant medications leading onto poor graft outcome is frequent among renal transplant recipients. In this study, we sought to assess the prevalence and correlates of nonadherence to immunosuppressants and its impact on graft function. A singlecenter, retrospective cum cross-sectional study of renal transplant recipients of age >18 years and who had completed at least six months after transplantation was performed. Nonadherence was assessed based on the Immunosuppressant Therapy Adherence Scale questionnaire. Factors attributed to nonadherence were assessed based on the Immunosuppressant Therapy Barriers Scale (ITBS) questionnaire. Social, economic, demographic data, and all transplant related information were recorded. Two hundred and seventy-nine patients were included in the study, of whom 78% were male. Median follow-up period was 46 months (interquartile range - 24 months to 82 months). Seventy-four patients (26.5%) admitted nonadherence to immunosuppressants. The nonadherence was significantly related to the male gender, late acute rejection episodes, rise in serum creatinine from > 0.5 mg/dL from nadir level, lower blood levels of calcineurin inhibitor, and higher ITBS scores. Refill rates and use of alarm reminders were not significantly associated with better adherence.

Clinical profile and outcome of pigment-induced nephropathy.

BACKGROUND: Pigment nephropathy represents one of the most severe complications of rhabdomyolysis or hemolysis. METHODS: We performed a retrospective observational study to analyze the etiology, clinical manifestation, laboratory profile and outcome in patients with biopsy-proven pigment-induced nephropathy between January 2011 and December 2016. History, clinical examination findings, laboratory investigations and outcome were recorded. RESULTS: A total of 46 patients were included with mean follow-up of 14 ± 5.5 months. Mean age was 40.15 ± 12.3 years, 65% were males (male:female, 1.8:1) and ∼37 (80.4%) had oliguria. Mean serum creatinine at presentation and peak creatinine were 7.5 ± 2.2 and 12.1 ± 4.3 mg/dL, respectively. Evidence of rhabdomyolysis was noted in 26 patients (64%) and hemolysis in 20 patients (36%). Etiology of rhabdomyolysis include snake envenomation (10 patients), seizures (7), strenuous exercise (5), wasp sting (2) and rifampicin induced (2). The causes of hemolysis include rifampicin induced (7 patients), sepsis (5), malaria (3), mismatched blood transfusion/transfusion reaction (3) and paroxysmal nocturnal hemoglobinuria (2). On renal biopsy, two patients had acute interstitial nephritis and two had immunoglobulin A deposits in addition to pigment nephropathy. All except one (97.8%) required hemodialysis (HD) during hospital stay and mean number of HD sessions was 9 ± 2. A total of three patients with sepsis/disseminated intravascular coagulation died, all had associated hemolysis. On statistical analysis, there was no difference between AKI due to rhabdomyolysis and hemolysis except for high creatine phosphokinase in patients with rhabdomyolysis and Lactate dehydrogenase level in patients with hemolysis. At mean follow-up, five patients (12%) progressed to chronic kidney disease (CKD). CONCLUSIONS: Pigment nephropathy due to rhabdomyolysis and hemolysis is an important cause of renal failure requiring HD. The prognosis was relatively good and depends on the etiology; however, long-term studies and follow-up are needed to assess the true incidence of CKD due to pigment nephropathy.