The superhydrophobic sponge decorated with Ni-Co double layered oxides with thiol modification for continuous oil/water separation

In this paper, the superhydrophobic polyurethane sponge(SS-PU) was facilely fabricated by etching with Jones reagent to bind the nanoparticles of Ni-Co double layered oxides(LDOs) on the surface, and following modification with n-dodecyl mercaptan(DDT). This method provides a new strategy to fabricate superhydrophobic PU sponge with a water contact angle of 157° for absorbing oil with low cost and in large scale. It exhibits the strong absorption capacity and highly selective characteristic for various kinds of oils which can be recycled by simple squeezing. Besides, the as-prepared sponge can deal with the floating and underwater oils, indicating its application value in handling oil spills and domestic oily wastewater. The good self-cleaning ability shows the potential to clear the pollutants due to the ultralow adhesion to water. Especially, the most important point is that the superhydrophobic sponge can continuously and effectively separate the oil/water mixture against the condition of turbulent disturbance by using our designed device system, which exhibit its good superhydrophobicity, strong stability.Furthermore, the SS-PU still maintained stable absorption performance after 150 cycle tests without losing capacity obviously, showing excellent durability in long-term operation and significant potential as an efficient absorbent in large-scale dispose of oily water.

Thiol Ligand-Modified Au for Highly Efficient Electroreduction of Nitrate to Ammonia

Electroreduction of nitrate(NO_(3)-)to ammonia(NH_(3))is an environmentally friendly route for NH_(3)production,serving as an appealing alternative to the Haber-Bosch process.Recently,various noble metal-based electrocatalysts have been reported for electroreduction of NO_(3)-.However,the application of pure metal electrocatalysts is still limited by unsatisfactory performance,owing to the weak adsorption of nitrogen-containing intermediates on the surface of pure metal electrocatalysts.In this work,we report thiol ligand-modified Au nanoparticles as the effective electrocatalysts toward electroreduction of NO_(3)-.Specifically,three mercaptobenzoic acid(MBA)isomers,thiosalicylic acid(ortho-MBA),3-mercaptobenzoic acid(meta-MBA),and 4-mercaptobenzoic acid(para-MBA),were employed to modify the surface of the Au nanocatalyst.During the NO_(3)-electroreduction,para-MBA modified Au(denoted as para-Au/C)displayed the highest catalytic activity among these Au-based catalysts.At-1.0 V versus reversible hydrogen electrode(vs RHE),para-Au/C exhibited a partial current density for NH_(3)of 472.2 mA cm^(-2),which was 1.7 times that of the pristine Au catalyst.Meanwhile,the Faradaic efficiency(FE)for NH_(3)reached 98.7%at-1.0 V vs RHE for para-Au/C.The modification of para-MBA significantly improved the intrinsic activity of the Au/C catalyst,thus accelerating the kinetics of NO_(3)-reduction and giving rise to a high NH_(3)yield rate of para-Au/C.

Unique role of non-mercapto groups in thiol-pinning- mediated Ag growth on Au nanoparticles

Owing to the strong affinity of thiols to Au and Ag, they are often employed to modify the surfaces of nanoparticles （NPs）. Recently, these strong ligand-interface interactions have been employed to control NP growth, and this technique has emerged as a unique modulation strategy for creating unconventional plasmonic hybrid nanostructures. In these systems, the roles of the non-mercapto components of the thiol molecules and their structures are still unknown. Therefore, we herein present our investigation into this phenomenon. Primary amino （-NH2） groups in thiols are found to play a key role in regulating growth kinetics, i.e., in accelerating Ag deposition on Au NPs. The -NH2 groups are thought to bring Ag ions to the particle surface by coordinating to them, and thereby assist their reduction. The effect of molecular structure is non-trivial and thus provides the possibility of selective thiol detection. Based on the dependence of kinetic modulation on the non-mercapto components and molecular structures of molecules, we demonstrate the highly sensitive and specific detection of cysteine （limit of detection： 6 nM） in a mixture of 19 natural amino acids based on Ag growth on Au nanospheres. In addition, based on this modulation effect, we reveal the entrapping of chiral thiols within the growth layer through their plasmonic circular dichroism （PCD） responses. We believe that thiol-based growth regulation has great potential for creating plasmonic nanostructures with novel functionalities.