Selective determination of acetone by carbon nanodots based on inner filter effect.

Fluorescent sensing of acetone has been achieved taking advantage of the unique optical property of acetone. However, the complicated synthesis process of the fluorescent probes limited their application. Here, carbon nanodots (CNDs) derived from glucose were chosen as the sensing material for the first time, which could be obtained by a one-pot microwave-assisted synthesis within 2 min. The CND had ultraviolet excitation spectrum, resulting in an obvious overlap between its excitation band with the absorption band of acetone. The fluorescent quenching occurred via inner filter effect with fast response. The CNDs showed sensitive response to acetone with a detection limit of 0.09 vol%, which was comparable to most previously reported MOF probes. The results of our work indicated the feasibility of IFE-based sensing method, and demonstrated an efficient and convenient way for acetone detection.

Gravure-printed interdigital microsupercapacitors on a flexible polyimide substrate using crumpled graphene ink.

In this paper, we demonstrate gravure printing of crumpled graphene ink to obtain a highly porous pattern of interdigitated electrodes, leading to an interdigital microsupercapacitor (MSC) on a flexible polyimide substrate. During the process of synthesizing crumpled graphene ink, Mg(OH)2 nanosheets as nanospacers were inserted into graphite oxide layers, resulting in sufficient crumples in graphene nanosheets to prevent the graphene sheets from restacking to enhance the ion transport and expose the electrochemical active area with oxygen-containing groups to provide more pseudo-capacitance. The gravure-printed interdigital MSCs achieved a high energy density (1.41 mW h cm(-3) at 25 mW cm(-3)) and high power density (0.35 mW h cm(-3) at 300 mW cm(-3)), respectively. Additionally, a liquid crystal display was driven by the two serial and two parallel connected MSCs for 35 s after charging for 3 s.

Graphene nanosheets inserted by silver nanoparticles as zero-dimensional nanospacers for dye sensitized solar cells.

Three-dimensional Ag nanoparticle/GNs (Ag/GNs) hybrids as highly efficient counter electrode (CE) materials for dye sensitized solar cells (DSSCs) is described, highlighting the Ag nanoparticles as zero-dimensional nanospacers inserting into GNs to lift the interspacing layer between individual GNs. It is demonstrated that, when the hybrids are used as CE materials for DSSCs, compared to their pure GNs, Ag/GNs hybrids without agglomerates have a significant improvement in their electrochemical properties such as high current density, narrow peak-to-peak separation (Epp) and low charge transfer resistance (RCT). The enhancement of electrochemical performance can be attributed to the increased electrode conductivity, an extended interlayer distance and the reduction of the restacking of graphene sheets due to the insertion of metallic Ag nanoparticles into GNs. The DSSC with this hybrid CE exhibited an energy conversion efficiency (η) of 7.72% with an open circuit voltage (VOC), short circuit photocurrent density (JSC), and fill factor (FF) of 732 mV, 14.67 mA cm(-2), and 71.8%, respectively.