You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

X-ray absorption spectroscopy and energy storage of Ni-doped cobalt nitride, (Ni(0.33)Co(0.67))N, prepared by a simple synthesis route. Metal nitride (Ni(0.33)Co(0.67))N nanoparticles are prepared by nitridation using NiCo(2)O(4) as a precursor material by heating at 335 °C for 2 h in flowing NH(3) + N(2) gas and characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), high resolution-transmission electron microscopy (HR-TEM), along with selective area electron diffraction (SAED) and X-ray absorption spectroscopy (XAS) techniques. The X-ray absorption near edge structure (XANES) at the Co K-edge showed that the oxidation state of cobalt is close to 3+. The (Ni(0.33)Co(0.67))N showed a shift in edge energy towards lower values due to Ni-doping to cobalt site. The Li-storage behaviour of (Ni(0.33)Co(0.67))N nanoparticles was evaluated by galvanostatic cycling and cyclic voltammetry in the cells with Li-metal as counter electrode in the voltage range of 0.005-3.0 V at ambient temperature. When cycled at 250 mA g(-1), the first-cycle reversible capacity of 700 (±5) mA h g(-1) (~1.9 moles of Li) is obtained. It showed an initial decrease in capacity until the 10(th) cycle and a stable capacity of 400 (±5) mA h g(-1) (~1.09 moles of Li) is observed at the end of the 50(th) cycle. Excellent rate capability is also shown when cycling at 500 mA g(-1) (up to 50 cycles). The materials showed excellent Li-ion insertion/extraction, with the coulombic efficiency reaching almost 99% in the range of 10-50 cycles. The average charge and discharge potentials are ~2.03 and ~1.0 V, respectively for the decomposition/formation of Li(3)N as determined by electroanalytical techniques.
{"Chemical": ["NiCo(2)O(4)", "cobalt nitride", "cobalt", "Co", "(Ni(0.33)Co(0.67))N", "N(2)", "Metal nitride", "Li", "NH(3)", "Li(3)N", "Ni"]}