Co-Pi decorated TiO 2 @graphitic carbon nitrides (g-C 3 N 4 ) nanorod arrays (denoted as CCNRs) with different mass ratios of g-C 3 N 4 have been constructed on the FTO substrate through three processes, hydrothermal growth, chemical bath deposition and electrodeposition. Firstly, TiO 2 nanorod arrays were grown onto a FTO substrate by a hydrothermal method. Secondly, g-C 3 N 4 was coated onto the TiO 2 nanorod arrays by immersing the above substrate with TiO 2 nanorod arrays into a solution of urea and then heated at higher temperature. In this procedure, the amount of the g-C 3 N 4 on the TiO 2 nanorod arrays can be controlled by tuning the concentration of the urea solution. At last, Co-Pi were decorated on the surface of the TiO 2 @g-C 3 N 4 by electrodeposition. The as-prepared CCNRs were characterized by XRD, FESEM, TEM, XPS, UV-vis and FTIR, respectively, which illustrated that Co-Pi were successfully decorated on the hybrid TiO 2 @g-C 3 N 4 nanorod arrays.Photoelectrochemical (PEC) measurements have demonstrated that the prepared CCNRs serve as an efficient and stable photoanode for PEC seawater splitting. The photocurrent density reaches 1.6 mA/cm 2 under 100 mW/cm 2 (AM1.5G) light illumination at 1.23 V (RHE). More significantly, the CCNRs photoanode is quite stable during seawater splitting and the performance remain undiminished even after ten hours continuous illumination. Finally, a systematical photocatalytic mechanism of the Co-Pi decorated TiO 2 @g-C 3 N 4 was proposed and it can be considered as potential explanation of enhanced PEC performance. .7 eV 35 , has attracted more and more attentions for its inherent chemical and thermal stability 36, 37 . Unlike transitional metal oxides and sulfide semiconductor photocatalysts, g-C 3 N 4 behaves very stable performance in acid or alkaline electrolytes ascribing to strong covalent bonds between carbon and nitride atoms in its structure 38 . However, applications of pure g-C 3 N 4 are limited largely because of its low quantum efficiency and high electron-hole recombination rate 39 .Therefore, it lays a large space to explore and construct novel composite materials to remedy these deficiencies of pure g-C 3 N 4 .Herein, we combined TiO 2 and g-C 3 N 4 to fabricate TiO 2 @g-C 3 N 4 nanorod arrays 40 with different mass ratios of g-C 3 N 4 via hydrothermal growth and chemical bath deposition. Moreover, the composite nanorod arrays were decorated with Co-Pi particles 41-43 to offset the inadequacy of g-C 3 N 4 44 . To the best of our knowledge, this is the first report upon semiconductor nanorod arrays modified with tunable g-C 3 N 4 mass ratio. As reported, Co-Pi decorated TiO 2 @g-C 3 N 4 nanorod arrays (CCNRs) used for photoelectrode within PEC cells are still unexplored. More importantly, the results in this work have proved that the composited nanorod arrays as photoelectrodes exhibit very efficient and stable performances for PEC seawater splitting.

A simply prepared gold nanoparticle-based sensor, 5,5'-dithiobis (2-nitrobenzoic acid) (DTNBA)-modified gold nanoparticles, was prepared to explore the sensitive and selective detection of metal ions using a colorimetric technique. The selective detection of trace levels (93.6 ppb) Cr3+ in aqueous solution was achieved over 15 other metal ions. The functionalized gold nanoparticles became aggregated in solution in the presence of Cr3+ by an ion-templated chelation process, which caused an easily measurable change in the extinction spectrum of the particles and provided an inherently sensitive method for Cr3+ detection in aqueous solution.

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We investigated the pressure-induced fluorescence enhancement of BSA-protected gold nanoclusters, AuNCs@BSA, and the corresponding conformational changes of ligand protein by in situ fluorescence and IR spectral measurements. It is documented that the fluorescence enhancement of AuNCs@BSA is essentially attributed to the conformational changes of the ligand, which undergoes substantial secondary and tertiary structural changes. Under compression BSA loses more buried α-helical structure, while it changes oppositely in the AuNCs@BSA as the protein adopts a more flexible conformational state at the boundary surface of gold nanoclusters. The present work will be helpful to understand the fundamental mechanism and to reveal the important factors of ligands in nanoclusters, which are hope to improve the luminescence efficiency of gold nanoclusters in final.

Anthracite is a plentiful and affordable natural resource with a high coalification degree and many graphene-like sp2 carbon crystallites, which is fascinating for the development of novel coal-based carbon materials to achieve the value-added utilization of coal resources. In this work, a facile one-step ultrasonic physical tailoring procedure for the fabrication of blue luminescent coal-derived graphene quantum dots (C-GQDs) was exploited using Taixi Anthracite as the carbon source. The as-prepared C-GQDs possess uniformly distributed sizes and diameters of 3.2 ± 1.0 nm, and their aqueous solution can remain in stable homogeneous phase even after 2 months at room temperature. Moreover, we found that the C-GQDs exhibit two different distinctive emission modes. The evolution of the surface states and the electronic structure analysis revealed that two different types of fluorescence centers could be ascribed to nanosized sp2 carbon domains and oxygen functional group defects. Meanwhile, unique electronic and chemical properties endow the C-GQDs with a sensitive response to Cu2+. C-GQDs were demonstrated as potential fluorescent materials for reliable, label-free, and selective detection of Cu2+, showing great promise in real-world sensor applications.