Luminescence properties of spark-processed porous graphite

The intent of this paper is to report the preparation of photoluminescing porous graphite using spark discharge in ambient air. The photoluminescence characteristics of spark-processed graphite had been studied at various temperatures. Properties of spark-processed graphite were studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. In addition to the luminescence peak of bulk graphite, the photoluminescence studies of spark-processed graphite at low temperature additionally revealed a sharp emission band in the UV (3.37 eV). As the temperature was decreased, PL spectra showed a continuous PL peak blue shift. XPS studies demonstrated a small incorporation of nitrogen on the surface of spark-processed graphite. With a combined analysis of XPS and Raman spectroscopy, one could detect nitrogen incorporation in the spark-processed graphite.