Ruoxi Wang

Theoretical Study of the Adsorption of Carbon Monoxide on Pristine and Silicon-Doped Boron Nitride Nanotubes

In order to explore the novel application of boron nitride nanotubes (BNNTs), we investigate reactivities of pristine and silicon-doped (Si-doped) (8,0) single-walled BNNTs towards the CO molecule by performing density functional theory calculations. Compared with weak physisorption on the pristine BNNT, the CO molecule presents strong chemical interaction with the Si-doped BNNT, as indicated by the calculated geometrical structures and electronic properties for these systems. It is suggested that doping BNNTs with silicon is expected to be a suitable strategy for adjusting the properties of BNNTs, and that Si-doped BNNTs are expected to find novel applications in nanotechnology.

A theoretical study of silicon-doped boron nitride nanotubes serving as a potential chemical sensor for hydrogen cyanide

In order to search for a novel sensor to detect and control exposure to hydrogen cyanide (HCN) pollutant molecule in environments, the reactivities of pristine and silicon-doped (Si-doped) (8, 0) single-walled boron nitride nanotubes (BNNTs) towards the HCN molecule are investigated by performing density functional theory (DFT) calculations. The HCN molecule presents strong chemisorption on both the silicon-substituted boron defect site and the silicon-substituted nitrogen defect site of the BNNT, which is in sharp contrast to its weak physisorption on pristine BNNT. A remarkable charge transfer occurs between the HCN molecule and the Si-doped BNNT as proved by the electronic charge densities. The calculated data for the electronic density of states (DOSs) further indicate that the doping of the Si atom improves the electronic transport property of the BNNT, and increases its adsorption sensitivity towards the HCN molecule. Based on calculated results, the Si-doped BNNT is expected to be a potential resource for detecting the presence of toxic HCN.

Silicon-doped carbon nanotubes: a potential resource for the detection of chlorophenols/chlorophenoxy radicals

Chlorinated phenols and chlorophenoxy radicals are known as predominant precursors for forming polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF), which are highly carcinogenic and persistent organic pollutants (POPs). Density functional theory (DFT) calculations have been carried out to explore the potential possibility of carbon nanotubes (CNTs) serving as the resource for detecting and/or adsorbing these PCDD/PCDF precursors. Based on the calculated results on a pristine (8, 0) CNT and a Si-doped (8, 0) CNT with and without the presence of a 2-chlorophenol (2-CP)/2-chlorophenoxy radical (2-CPR), the typical representative of chlorophenols/chlorophenoxy radicals, we propose that pristine carbon nanotubes (CNTs) may be unsuitable for the desired applications due to their poor capability for catching chlorinated phenols/chlorophenoxy radicals, on the other hand, Si-doped CNTs are expected to be a potential resource for detecting and/or adsorbing (concentrating) these PCDD/PCDF precursors. The present results provide a guide to the relevant experimentalists, who are exploring novel applications of CNT-based materials in nanoscience and nanotechnology, and/or searching for suitable resources for detecting chlorophenols/chlorophenoxy radicals.

Theoretical study of the adsorption of pentachlorophenol on the pristine and Fe-doped boron nitride nanotubes.

AbstractTo explore the novel application of boron nitride nanotubes (BNNTs), we investigated the interaction of pentachlorophenol (PCP) pollutant with the pristine and Fe doped (Fe-doped) (8, 0) single-walled BNNTs by performing density functional theory calculations. Compared with the weak physisorption on the pristine BNNT, PCP molecule presents strong chemisorption on the Fe-doped BNNT. The calculated data for the electronic properties indicate that doping Fe atom into the BNNT significantly improves the electronic transport property of BNNT, induces magnetism in the BNNT, and increases its adsorption sensitivity toward PCP molecule. It is suggested that doping BNNTs with Fe is an available strategy for improving the properties of BNNTs, and that Fe-doped BNNT would be a potential resource for adsorbing PCP pollutant in environments. FigureThe Fe-doped BNNT presents high sensitivity to PCP pollutant and is expected to be a potential resource for adsorbing toxic pentachlorophenol molecule.

A New Pathway for Activation of C–C and C–H Bonds by Transition Metals in the Gas Phase

C–H and C–C bond activation of hydrocarbons at metal centres are of fundamental importance in biochemistry, organometallic chemistry, and catalysis. The present work aims to search for novel mechanisms for activation of C–C and C–H bonds by transition metals in the gas phase. Using high-level density functional calculations, we systemically studied the reactions of Ti+, V+, and Fe+ with ethane, and proposed new pathways of C–C and C–H bond activation—concerted activation of C–C and C–H bonds, and 1,2-H2 elimination. These two pathways clearly differ from the general addition–elimination mechanism.