title: Pine needle-derived microporous nitrogen-doped carbon frameworks exhibit high performances in electrocatalytic hydrogen evolution reaction and supercapacitors.
abstract: The design of electrochemically active materials with appropriate structures and compositions is very important for applications in energy conversion and storage devices. Herein, we demonstrate an effective strategy to prepare microporous heteroatom-doped carbon frameworks derived from naturally-abundant pine needles. The preparation procedure is based on the carbonization of pine needles, followed by KOH activation at a temperature range of 700-1000 °C. The resultant nitrogen-doped carbon consists of abundant micropores and an ultrahigh specific surface area (up to 2433 m2g-1), leading to high performances in electrocatalytic hydrogen evolution reaction (HER) and supercapacitors. Specifically, when the pine needle-derived carbon (activated at 800 °C) serves as a HER electrocatalyst, it exhibits a low onset potential (∼4 mV), a small Tafel slope (∼45.9 mV dec-1) and a remarkable stability over long-term cycling. When evaluated as an electrode material for supercapacitors, the pine needle-derived carbon (activated at 900 °C) demonstrates high specific capacitance (236 F g-1at 0.1 A g-1), remarkable rate capability (183 F g-1at even 20 A g-1) and good long-term stability. Notably, the specific capacitance at 2.0 A g-1increased from ∼205 to ∼227 F g-1after cycling for 5000 times, owing to the further activation and wetting of the electrodes. This novel and low-cost biomass-derived carbon material is very promising for many applications, especially in electrocatalytic water splitting and supercapacitors.
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Guoyin
authors.initials: G
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Lianbo
authors.initials: L
authors.lastname: Ma
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Hongling
authors.initials: H
authors.lastname: Lv
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Yi
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Renpeng
authors.initials: R
authors.lastname: Chen
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Jia
authors.initials: J
authors.lastname: Liang
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Yanrong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Changzeng
authors.initials: C
authors.lastname: Yan
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Zuoxiu
authors.initials: Z
authors.lastname: Tie
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Jin
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China. zhongjin@nju.edu.cn j.liu@duke.edu and Department of Chemistry, Duke University, Durham, NC 27708, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu