A study on the Fabrication of Nanoparticle - Carbon Nitride Nanotube Hybrids and their application as a catalyst

Abstract

Metal nanoparticles (NPs) with a zero-dimensional structure have attracted a lot of attention to many researchers of state-of-the-art applications such as electronic, magnetic, and optical devices and metal NPs have been used as both homogeneous and heterogeneous catalysts. However, most of metal NPs still involve agglomeration of NPs, and they result in a decline of their original activity. NP-Host structure material hybrids can be a good alternative to solve the problem of NPs agglomeration because host structure materials attach NPs on the surface and control the movement of NPs. Carbon nitride nanotubes (CNNTs) including heterogeneous nitrogen in the carbon network on the Carbon nanotubes (CNTs) can be used as the host structure material because of high binding energy with metal NPs on the surface. In addition, CNNTs can provide defects to anchor NPs on the carbon network surface via direct growth without an additional functionalization process such as an acid solution treatment, which can cause damage to the carbon network surface of CNTs. In this Dissertation, cobalt or cobalt oxide nanoparticles (Co or Co3O4 NPs)-CNNTs hybrids with a uniform distribution and no agglomeration of NPs on the surface of CNNTs were fabricated through new synthesis routes. In addition, Co or Co3O4 NPs-CNNTs hybrids materials were applied to the hydrogen generation rate from aqueous metal hydride (NaBH4) solution and to the peroxidase-like activity of organic substrate (TMB) with the existence of H2O2 as a catalyst, respectively. First, Co NPs - CNNTs hybrids were fabricated to be based on the reduction of Co precursor on CNNTs in the presence of sodium hypophosphite, water and hydroxyl ion in alkaline ethylene glycol solution. Sodium hypophosphite acts as reducing agent of Co NPs. The size of Co NPs fabricated above method is controlled to about 2 nm. According to the increase of sodium hypophosphite concentration during the synthesis process, the scale of ...