The non-aqueous synthesis of shape controllable Cu2-xS plasmonic nanostructures in a continuous-flow millifluidic chip for the generation of photo-induced heating

Tai Lok Cheung, Liying Hong, Nanxi Rao, Chengbin Yang, Libo Wang, Wenn Jing Lai, Peter Han Joo Chong, Wing Cheung Law, Ken Tye Yong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

17 Citations (Scopus)

Abstract

In this paper, a new method for synthesizing non-aqueous copper sulfide nanocrystals with different shapes and sizes using a homemade continuous-flow millifluidic chip is presented. Conventionally, the shape control of nanocrystals was accomplished using a surfactant-controlled approach, where directional growth is facilitated by selective passivation of a particular facet of the nanocrystals using surfactants. We demonstrate a "surfactant-free" approach where different sizes and shapes (i.e. spherical, triangular prism and rod) of plasmonic copper sulfide (Cu2-xS) nanocrystals can be fabricated by adjusting the flow rate and precursor concentrations. As continuous-flow synthesis enables uniform heating and easy variation of precursors' stoichiometries, it serves as an excellent incubation platform for nanoparticles due to its simplicity and high reproducibility. Transmission electron microscopy (TEM), fast Fourier transform (FFT) and X-ray diffraction (XRD) techniques were used to characterize the as-synthesized nanocrystals and revealed structures ranging from copper-deficient covellite (CuS), spionkopite (Cu1.39S), roxbyite (Cu1.75S), to copper-rich djurleite (Cu1.94S). The localized surface plasmon resonance (LSPR) peak of the nanocrystals can be tuned from 1115 to 1644 nm by simply varying the copper to sulfur molar ratio and flow rate. Furthermore, photothermal effects of Cu2-xS nanocrystals were also demonstrated to annihilate the RAW264.7 cells upon near infra-red laser irradiation.
Original languageEnglish
Pages (from-to)6609-6622
Number of pages14
JournalNanoscale
Volume8
Issue number12
DOIs
Publication statusPublished - 28 Mar 2016

ASJC Scopus subject areas

  • Materials Science(all)

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