Green anhydrous assembly of carbon dots via solar light irradiation and its multi-modal sensing performance

• DOI: 10.1016/j.dyepig.2019.02.037
• Publication Date: 2019-02-25T02:52:22Z
• Authors: Dong Lu; Yiping Tang; Jinwei Gao; Ying Chen; Qianming Wang
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

Abstract A simple, rapid and low-cost solar irradiation method to prepare highly fluorescent carbon dots has been demonstrated by using citric acid and o-phenylenediamine as precursors. The whole concentrated light sintering process is completed within 2 min and this nitrogen doped carbon quantum dots exhibit striking blue luminescence. Except the conventional ultra-violet (378 nm) pumped emissions, the specific up-converted photoluminescence signal is able to extend the excitation sources to near-infrared range (750 nm). Moreover, carbon dots are very sensitive and selective to the presence of Hg2+ ions. Two different responsive ways (down-conversion and up-conversion) have been employed for the first time and the limits of detection are determined to be 1.3 nM and 0.06 nM respectively. Its pH dependence has been discussed and the evolution curves indicate such carbon-based nanomaterial possess unique features within a wide pH range. This study focuses on efficient solar energy conversion and provides new insights of carbon dots with multi-modal sensing capabilities.