Facile Synthesis of Platinum–Cerium(IV) Oxide Hybrids Arched on Reduced Graphene Oxide Catalyst in Reverse Micelles with High Activity and Durability for Hydrolysis of Ammonia Borane

Abstract

Highly dispersed Pt-CeO hybrids arched on reduced graphene oxide (Pt-CeO /rGO) were facilely synthesized by a combination of the reverse micelle technique and a redox reaction without any additional reductant or surfactant. Under a N atmosphere, the redox reaction between Ce and Pt occurs automatically in alkaline solution, which results in the formation of Pt-CeO /rGO nanocomposites (NCs). The as-synthesized Pt-CeO /rGO NCs exhibit superior catalytic performance relative to that shown by the free Pt nanoparticles, Pt/rGO, Pt-CeO hybrid, and the physical mixture of Pt-CeO and rGO; furthermore, the nanocomposites show significantly better activity than the commercial Pt/C catalyst toward the hydrolysis of ammonia borane (NH BH ) at room temperature. Moreover, the Pt-CeO /rGO NCs have remarkable stability, and 92 % of their initial catalytic activity is preserved even after 10 runs. The excellent activity of the Pt-CeO /rGO NCs can be attributed not only to the synergistic structure but also to the electronic effects of the Pt-CeO /rGO NCs among Pt, CeO , and rGO.

In‐Situ Synthesis of Tetraphenylporphyrin/Tungsten (VI) Oxide/Reduced Graphene Oxide (TPP/WO3/RGO) Nanocomposite for Visible Light Photocatalytic Degradation of Acid Blue 25

“…The BET surface area was used to determine the specific surface area of the different materials and the results are summarised in table . The specific surface area of RGO is high (432.1 m 2 /g) but is low when compared to theoretical value of RGO . Moreover, nanoparticles loading significantly decreased the pore volume but increased the average pore diameter and the surface area of TWR3 350 (470.1 m 2 /g).…”

“…The (002) reflections (2θ=26.9) corresponding to RGO is present with the intensity of the peak around 2θ=11 being absent which indicates that the prepared reduced graphene oxide (RGO) has little amount of various oxygen containing functionalities and intercalated molecules present as confirmed by the EDS and the FTIR results. Thus, it can be inferred that the RGO maintained the crystal structure of natural graphite …”

“…The peak at 1638 cm −1 is due to the C=O stretching vibration of carbonyl functional group in RGO and overlapped with the aromatic C=C stretching of TPP. Further, peaks at 2859 and 2926 cm −1 were attributed to the symmetric and asymmetric stretching vibrations of CH bonds respectively . The broad peak between 400–800 cm −1 were due to several vibration modes of CH like outer bending vibration, CH in plane bending, CH out of plane wagging of aromatic systems.…”

“…Further, peaks at 2859 and 2926 cm −1 were attributed to the symmetric and asymmetric stretching vibrations of CH bonds respectively . The broad peak between 400–800 cm −1 were due to several vibration modes of CH like outer bending vibration, CH in plane bending, CH out of plane wagging of aromatic systems. A broad peak at 3465 cm −1 presented by RGO could be attributed to the OH bond stretching vibrations belonging to COH and/or adsorbed moisture.…”

“…Furthermore, TiO 2 , has widely been studied because its energy band levels (valence and conductance) are favourable for redox water splitting reactions . Besides TiO 2 , the other metal oxide semiconductors (MOSs) that have been studied for photocatalysis include vanadium oxide, (V 2 O 5 ) tungsten oxide (WO 3 ) zinc oxide (ZnO) and zirconium dioxide (ZrO 2 ) . Among transition metal oxides, WO 3 is the second most studied material as it exhibit a number of useful properties.…”