title: Nitrogen and phosphorus dual-doped graphene as a metal-free high-efficiency electrocatalyst for triiodide reduction.
abstract: Alternative high-performance electrocatalysts for triiodide (I3-) reduction of low-cost dye-sensitized solar cells (DSSCs) are urgently sought after. To address the concerned issues, we report a facile strategy for engineering the nitrogen and phosphorus dual-doped graphene (NPG) via an efficient ball-milling process, followed by a simple thermal annealing approach utilizing melamine (C3H6N6) and triphenylphosphine ((C6H5)3P) as the N and P source, respectively. When employed as the counter electrode (CE) in DSSCs, such a metal-free material exhibits excellent electrocatalytic activity towards the I3-/I-redox reaction. Dual-doping of N and P heteroatoms can markedly enhance the photovoltaic performance of DSSCs by a synergistic effect and a high conversion efficiency of 8.57% is achieved, which is superior to Pt CE, and much higher than that of the single-component N- or P-doped graphene electrodes. In addition, the NPG CE also shows an outstanding electrochemical stability. The present results demonstrate that the NPG as a low-cost and high-efficiency electrocatalyst for reduction of I3-will be one of the promising CE materials in DSSCs.
authors.affiliation: State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China. carbon@dlut.edu.cn.
authors.forename: Chang
authors.initials: C
authors.lastname: Yu
authors.affiliation: State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China. carbon@dlut.edu.cn.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Liu
authors.affiliation: State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China. carbon@dlut.edu.cn.
authors.forename: Xiangtong
authors.initials: X
authors.lastname: Meng
authors.affiliation: State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China. carbon@dlut.edu.cn.
authors.forename: Bing
authors.initials: B
authors.lastname: Lu
authors.affiliation: State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China. carbon@dlut.edu.cn.
authors.forename: Dan
authors.initials: D
authors.lastname: Cui
authors.affiliation: State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China. carbon@dlut.edu.cn.
authors.forename: Jieshan
authors.initials: J
authors.lastname: Qiu