In Situ Raman Monitoring of Trace Antibiotics in Different Harsh Water Environments

In situ surface-enhanced Raman scattering(SERS)is a widely used operando analytical technique,while facing numerous complex factors in applications under aqueous environment,such as low detection sensitivity,poor anti-interference capability,etc.,resulting in unreliable detectability.To address these issues,herein a new hydrophobic SERS strategy has been attempted.By comprehensively designing and researching a SERS-active structure of superhydrophobic ZnO/Ag nanowires,we demonstrate that hydrophobicity can not only draw analytes from water onto substrate,but also adjust"hottest spot"from the bottom of the nanowires to the top.As a result,the structure can simultaneously concentrate the dispersed molecules in water and the enhanced electric field in structure into a same zone,while perfecting its own anti-interference ability.The underwater in situ analytical enhancement factor of this platform is as high as 1.67×10^(11),and the operando limited of detection for metronidazole(MNZ)reaches to 10^(-9)M.Most importantly,we also successfully generalized this structure to various real in situ detection scenarios,including on-site detection of MNZ in corrosive urine,real-time warning of wrong dose of MNZ during intravenous therapy,in situ monitoring of MNZ in flowing wastewater with particulate interference,etc.,demonstrating the great application potential of this hydrophobic platform.This work realizes a synergistic promotion for in situ SERS performance under aqueous environment,and also provides a novel view for improving other in situ analytical techniques.

Removal of toxic metal ions using chitosan coated carbon nanotube composites for supercapacitors

Environmental pollution and energy crisis are two major global challenges to human beings.Recovering energy from wastewater is considered to be one of the effective approaches to address these two issues synchronously.As the main pollutants in wastewater,toxic heavy metal ions are the potential candidates for energy storage devices with pseudocapacitive behaviors.In this study,toxic metal ions of Cr(VI)and Cu(II)are removed efficiently by chitosan coated oxygen-containing functional carbon nanotubes,and the corresponding equilibrium adsorption capacity is 142.1 and 123.7 mg g^(-1).Followed by carbonization of metal ions-adsorbed adsorbents,Cu-and Cr N-loaded carbon composites can be obtained.Electrochemical measurements show that the supercapacitor electrodes based on Cu-and Cr N-loaded carbon composites have specific capacitance of 144.9 and 114.9 F g^(-1)at2 m V s^(-1),with superior electrochemical properties to pure chitosan coated carbon nanotubes after carbonization.This work demonstrates a new strategy for the resource-utilization of other heavy metal ions for energy devices,and also provides a new way to turn environmental pollutants into clean energy.

Novel(Ni, Fe)S2/(Ni, Fe)3S4 solid solution hybrid: an efficient electrocatalyst with robust oxygen-evolving performance

Fabrication of high-activity electrocatalysts with operational stability is desperately needed to achieve efficient energy conversion.Herein,for the first time,we highlight a novel electrocatalyst based on binary nickel iron sulfide solid solution hybrids on carbon cloth for oxygen evolution reaction.Benefitting from the synergistic effect of varied phases and the interfacial connection between(Ni,Fe)S2 and(Ni,Fe)3S4 to accelerate the charge transport,the Ni incorporation to optimize the electronic structure of the hybrids and the downshift of the d-band center to facilitate the desorption of oxygen intermediates,the partial charge-transfer between Fe and Ni to boost the generation of catalytically active Ni3+as well as the unique nanosphere structure to offer enough buffer area for the volume changes during constant redox reactions,the obtained binary nickel iron sulfide hybrids((Ni,Fe)S2/(Ni,Fe)3S4)display high catalytic reactivity with a low overpotential of 210 mV to reach the current density of 10 mA cm-2,and excellent stability with negligible activity deterioration,making the hybrid a promising candidate for electrocatalytic alkaline water oxidation.