Double-walled heterostructured Cu2−xSe/Cu7S4 nanoboxes with enhanced electrocatalytic activity for quantum dot sensitized solar cells. Issue 37 (13th September 2017)

• Record Type: Journal Article
• Authors: Ran, Lei; Yin, Longwei
• Is Part Of: CrystEngComm. Volume 19:Issue 37(2017)
• Page Start: 5640
• Page End: 5652
• Publication Date: 2017-09-13
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/c7ce01112a
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : The double-walled heterostructured Cu2− x Se/Cu7 S4 nanoboxes prepared by an inward etching/sacrificial template method show promoted electrocatalytic activity in QDSSCs. Abstract : It is of great importance to develop counter electrodes (CEs) as an alternative for enhancing the power conversion efficiency (PCE) of quantum dot sensitized solar cells (QDSSCs). Here, single-walled Cu7 S4 nanoboxes (SW-Cu7 S4 -NBs) and double-walled heterostructured Cu2− x Se/Cu7 S4 nanoboxes (DW-Cu2− x Se/Cu7 S4 -HNBs) are synthesized by a facile in situ inward etching/sacrificial template method based on the Kirkendall effect. A remarkably enhanced and stable electrocatalytic activity is achieved for the QDSSC based on the DW-Cu2− x Se/Cu7 S4 -HNB CE, which is inclusively derived from the high intrinsic electron conductivity of Cu2− x Se, the stimulated electron transfer process and abundant active catalytic sites due to the enlarged specific surface area, higher utilization efficiency of incident light of the unique double-walled hollow structure, and the formation of a heterogeneous nanostructure. As a result, the QDSSC based on the DW-Cu2− x Se/Cu7 S4 -HNB CE exhibits a PCE of 4.38% under 1 sun (100 mW cm −2 ) irradiation, while 3.97%, 3.43% and 1.54% were found for SW-Cu7 S4 -NB, Pt and brass/Cu2 S based CEs, respectively. Furthermore, it is suggested that the DW-Cu2− x Se/Cu7 S4 -HNB CE still shows superior long-term stability towards the polysulfide electrolyte even after 600 cycles.