Synthesis and characterization of a new catalyst for RhB degradation constructed by[SiMo_(12)O_(40)]^(4-) anionic cluster

A Keggin-type polyoxomolybdate[H2biim]{Ni（biim）3（SiMO12O40）}[biim =1H,1＇H-[2,2＇]biimidazolyl]has been synthesized under hydrothermal condition and characterized by XRD,temperature-dependent IR,TG,temperature-induced and magnetism-induced 2D infrared correlation spectroscopy（2D-IR COS）and UV-vis DRS in order to explore the relationship between structure and properties.Temperatureinduced 2D-IR COS spectroscopy indicates that the terminal Mo-Oμ/υbonds are more sensitive than the bridging Mo=Ot,bands to temperature variation,which is in agreement with the conclusion of temperature-dependent IR.Magnetism-dependent 2D-IR COS spectroscopy reveals the stretching vibration of the Mo=Ot,occurs prior to the stretching vibration of the Mo-Oμ/υ,which is due to the coordination environment and the valence of the Si atom.The stability of compound 1 is investigated via TG and temperature-dependent IR.In RhB degradation,compound 1 shows good photocatalytic abilities.

Synthesis and Visible-light Photocatalytic Performance of C-doped Nb2O5 with High Surface Area

C-doped Nb2O5 with abundant mesopores has been successfully synthesized through a facile solvothermal synthetic strategy followed by calcination treatment. The resulting C-doped Nb2O5 displayed the highest BET surface area（345 m^2/g） and large mesopore size（ca. 4.2 nm）, capable of offering more accessible active sites as well as faster mass transfer for catalysis. Besides, the doping of C（2.21%, molar fraction） at the O sites in Nb2O5 lattice greatly enhanced visible-light response by lowering the band gap, thereby making the material a photocatalyst under visible-light irradiation. Typically, the C-doped Nb2O5 exhibited a high H2 evolution rate of ca. 39.10·μmol·g^-1·h^-1 and also degraded RhB dye completely after 30 min of visible light exposure, which turned out to be much better than Degussa P25 and pure Nb2O5 catalysts.

Graphene-like h-BN supported polyhedral NiS_(2)/NiS nanocrystals with excellent photocatalytic performance for removing rhodamine B and Cr(Ⅵ)

Human health is deteriorating due to the effluent containing heavy metal ions and organic dyes.Hence,photoreduction of Cr(Ⅵ)to Cr(Ⅲ)and degradation of rhodamine B(RhB)using a novel photocatalyst is particularly important.In this work,h-BN/NiS_(2)/NiS composites were prepared via a simple solvothermal method and a double Z-scheme heterojunction was constructed for efficiently removing RhB and Cr(Ⅵ).The 7 wt-%h-BN/NiS_(2)/NiS composites were characterized via a larger specific surface area(15.12 m^(2)·g^(−1)),stronger light absorption capacity,excellent chemical stability,and high yield of electrons and holes.The experimental result indicated that the photoreduction efficiency of the 7 wt-%h-BN/NiS_(2)/NiS photocatalyst achieved 98.5%for Cr(Ⅵ)after 120 min,which was about 3 times higher than that of NiS_(2)/NiS(34%).However,the removal rate of RhB by the 7 wt-%h-BN/NiS_(2)/NiS photocatalyst reached 80%.This is due to the double Z-scheme heterojunction formed between NiS_(2)/NiS and h-BN,which improved the charge separation efficiency and transmission efficiency.Besides,the influence of diverse photogenerated electron and hole scavengers upon the photoreduction of Cr(Ⅵ)was studied,the results indicated that graphene-like h-BN promoted transportation of photoinduced charges on the surface of the h-BN/NiS_(2)/NiS photocatalyst via the interfacial effects.