Fabrication of GO/NH4NO3 composite films by vacuum filtration as laser converter for enhanced photothermal performance

Abstract

Graphene-based materials have been extensively investigated as light converters for photothermal therapy, energy harvesting, and laser ignition owing to their good light absorption and high thermal conductivity. Further, the energy output of pure graphene materials as laser converters is relatively low. In this paper, we reported the introduction of ammonium nitrate (AN) into graphene oxide (GO) for the preparation of free-standing, graphene-based membranes using anti-solvent method and vacuum filtration. They showed good light absorption and energy output, leading to excellent photothermal performance owing to the synergistic reaction between GO and AN. The existence of AN was confirmed by scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy analyses. The influence of GO and NH4NO3 on the photothermal performance of the composite membranes was entirely investigated by ultraviolet, thermal gravimetric analysis, and differential scanning calorimetry analyses. The heat release and the maximum heat release rate of the G20N5 film were 1030 ​J·g−1 and 8.9 ​J·g−1s−1, respectively, which were much higher than those of the pure GO. The flame produced by the laser irradiation was captured by a high-speed camera. The prepared G20N5 film showed the best performance among all the samples. Compared with pure GO (approximately 300 ​°C at 0.7 ​W), the temperature of the G20N5 composite film was dramatically increased (approximately 450 ​°C at 0.7 ​W) under the same power of the pulse laser irradiation, which is important for the potential application of optical ignition with low initiating energy.

Keywords

• Photothermalperformance
• Graphene oxide
• Ammonium nitrate
• Free-standing membranes