Nitrogen-doped graphene quantum dots anchored on NiFe layered double-hydroxide nanosheets catalyze the oxygen evolution reaction. (9th October 2020)

• Record Type: Journal Article
• Authors: Dong, Qibing; Shuai, Chao; Mo, Zunli; Liu, Zhenyu; Liu, Guigui; Wang, Jia; Chen, Ying; Liu, Wentong; Liu, Nijuan; Guo, Ruibin
• Is Part Of: New journal of chemistry. Volume 44:Number 41(2020)
• Page Start: 17744
• Page End: 17752
• Publication Date: 2020-10-09
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d0nj03537h
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : N-GQDs/NiFe-LDH layered nanosheet structure has excellent OER catalytic performance. Abstract : The design and synthesis of efficient, durable, low-cost catalysts are vital for the oxygen evolution reaction (OER) because it is an important process in energy conversion and storage. Here, we describe the use of a simple hydrothermal process to successfully synthesize novel nitrogen-doped graphene quantum dots (N-GQDs) anchored on NiFe layered double hydroxide sheets (N-GQDs/NiFe-LDH). Structural, morphological, and crystalline phase characteristics were confirmed by applying SEM, TEM, XPS, and XRD studies. These analyses clearly showed the formation of the N-GQDs/NiFe-LDH composite with a hierarchical nanosheet structure possessing higher surface area values and a wide range of pores (10–180 nm). Further study showed that the as-prepared N-GQDs/NiFe-LDH composite exhibited excellent electrocatalytic activity for the OER in alkaline solution, affording small overpotential of 279 and 300 mV at current densities of 20 and 50 mA cm −2, respectively, a low Tafel slope of 47 mV dec −1, and satisfactory stability. The outstanding reactive kinetics outperformed those of most previously reported transition-metal-based catalysts. The excellent OER catalytic activity for the N-GQDs/NiFe-LDH composite is attributed to the synergistic effect of the N-GQDs and NiFe-LDH, the existence of pyridinic-N and graphitic-N on the N-GQDs, and the hierarchical nanosheet and its porous structure. This work provides a new strategy for designing and fabricating novel carbon-based LDH composites.