Unveiling the surface of carbon black via scanning probe microscopy and chemical state analysis
Mari Isagoda,
Yuto Ariyoshi,
Yuto Fujita,
Sae Endo,
Takayuki Aoki,
Rui Tang,
Hirotomo Nishihara,
Tomoko K. Shimizu
Affiliations
Mari Isagoda
Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa, 223-8522, Japan
Yuto Ariyoshi
Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa, 223-8522, Japan
Yuto Fujita
Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa, 223-8522, Japan; Innovative Photon Manipulation Research Team, RIKEN Center for Advanced Photonics, Hirosawa, Wako, Saitama 351-0198, Japan
Sae Endo
Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa, 223-8522, Japan
Takayuki Aoki
Asahi Carbon Corporation, Higashi-ku, Niigata 950-0883, Japan
Rui Tang
College of Materials Science and Engineering, Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy, Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, Hunan University, Changsha 410082, China; Advanced Institute for Materials Research (WPI-AIMR) / Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
Hirotomo Nishihara
Advanced Institute for Materials Research (WPI-AIMR) / Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
Tomoko K. Shimizu
Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa, 223-8522, Japan; Corresponding author.
Carbon black (CB) has wide range of industrial applications, including in the manufacturing of automobile tires, rubber products, inks, and plastics. To improve the properties of the target products and establish recycling systems, it must be fully characterized. However, characterization of CB is challenging owing to its structural complexity and the limitation of conventionally used experimental techniques, especially for surface structures at the nanoscale. In this study, we characterized the surface structures of two commercial CB via atomic force and scanning tunneling microscopy. Analysis of well-dispersed aggregates on atomically flat solid surfaces revealed primary particles of diverse sizes. The particle surfaces lacked edges, grooves, and steps that should be observed between stacked graphene sheets, which contradicts the widely accepted crystallite model. Observed images suggest that the graphene sheets exhibit a size distribution, inferring that multiple non-uniformly sized small graphene sheets are stacked turbostratically, with each sheet displaying a localized curvature rather than the ideal planar form. Varying size of sheets and curvature indicate the presence of a decent number of edges terminated with hydrogen and oxygen-containing functional groups. This interpretation was corroborated by conventional spectroscopic techniques: Raman spectroscopy, X-ray photoelectron spectroscopy, temperature-programmed desorption, and infrared absorption spectroscopy.
