In the present work, graphene samples were obtained from graphene oxide (GO) by a direct hydrothermal method, using thermogravimetry-differential thermal analysis to ascertain changes in mass as well as the oxidization temperature. Thermal analysis-mass spectrometry was also used to assess the generation of H2O + (m/z = 18) and CO 2+ (m/z = 44) ions over the temperature range of 400-650°C. On the basis of the resulting data, the mass loss of the GO during the oxidation process is attributed to the loss of H2O and CO2. The thermal kinetics of graphene under ambient air were also studied at heating rates of 5, 10, and 15°C•min -1 . The activation energy (Ea) and logarithm of pre-exponential factor (lg(A/s -1 )) values calculated by the Kissinger method were 155.11 kJ•mol -1 and 6.90. The dependence of Ea and lgA on the extent of conversion, α, were also calculated, using the Ozawa-Flynn-Wall (FWO) method. The results of this work provide a frame of reference for the use of graphene in thermal applications, such as in thermal interface and thermal conductive materials, advanced composites and materials synthesis.

摘要：钙钛矿结构 SrSnO3因其独特的介电和半导体性质而备受关注，通过掺杂可显著调控其电学、磁学性 能，拓宽其应用范围。本研究在单晶 SrTiO3(001)衬底上通过脉冲激光方法外延生长了 SrSn1-xCoxO3 (x = 0, 0.16, 0.33, 0.5) (SSCO)薄膜，探究了 Co 含量对薄膜结晶性、微观结构、光学性能以及介电性能的影响。结 果表明，SrSn1-xCoxO3薄膜可在 SrTiO3(001)衬底上外延生长，Co 掺杂不会导致薄膜结晶质量的劣化。薄膜表 面形貌平整、致密，膜厚 200 nm，表面粗糙度为 0.44 nm。随薄膜中 Co 掺杂量增加，薄膜透过率从 90%降