Abstract

Nickel-palladium bimetallic nanocrystallite supported mesoporous silica/silica nanoparticles (MSPs/MSNPs) made at a controlled ratio of Pd/Ni via organotrialkoxysilane mediated reduction of palladium cations are reported. The organotrialkoxysilane serve as a template for the stabilization and formation of bimetallic Pd-Ni nanocrystallite within MSPs/MSNPs that are characterized by TEM, EDX, HR-SEM, HR-MS, XRD, BET and Elemental mapping analysis, kinetic analysis for degradation of both cationic and anionic dyes, i.e., rhodamine B and congo red, respectively. The nanocrystallite inserted MSNPs of particle diameter 200 nm justify faster degradation with rate constant to the order of 6.9 x10⁻²s⁻¹ as compared to that for MSPs of 50 µm to the order of 3.2 x10⁻² s⁻¹ for 15 ppm Rh B within 50 s as compared to that for mesoporous silica of 50 µm within 110 s under similar conditions with analogous observation for the degradation of congo red. Heterogeneous support is fully recyclable and shows 100% catalytic activity even after five subsequent applications. The degradation dynamics have further been evaluated based on fluorescent spectra and HR-MS analysis.

摘要

报道了通过有机三烷氧基硅烷介导的钯阳离子还原以受控的Pd / Ni比例制备的镍-钯双金属纳米微晶负载的介孔二氧化硅/二氧化硅纳米粒子（MSPs / MSNPs）。有机三烷氧基硅烷可作为MSP / MSNP中双金属Pd-Ni纳米微晶稳定和形成的模板，其特征在于TEM，EDX，HR-SEM，HR-MS，XRD，BET和元素图分析，动力学分析以降解阳离子和阴离子染料，如罗丹明B和刚果红。与50 µm的MSP到3.2 x10 ^-2 s的MSP相比，插入纳米颗粒的200nm粒径的MSNP证明了更快的降解速度，速率常数为6.9 x10 ^-2 s ^-1。与在类似条件下观察到的刚果红降解情况相似，在110 s内在50 s内15 ppm Rh B与在110 s内在50 µm的中孔二氧化硅相比，^-1。异质载体可以完全回收利用，即使在随后的五次应用后仍显示出100％的催化活性。基于荧光光谱和HR-MS分析进一步评估了降解动力学。