Hydrogen Storage Studies of Nanocomposites Derived From O-Ethyl-S-((5-Methoxy-1H-Benzo[d]Imidazol-2-Yl)Carbonothioate (OESMBIC) With ZnO and TiO2 Nanoparticles

Abstract

5-Methoxy-2-mercaptobenzamidazole was used to synthesize O-ethyl-S-(5-methoxy-1H-benzo[d]imidazol-2-yl) carbonothioate (OESMBIC) by the reaction with chloroacetic acid ethyl ester in a KOH solution. The reaction product (OESMBIC) was characterized using Fourier transform infrared (FTIR), melting point, and ¹H-NMR. The characteristic results prove the formation of the target compound with high purity. Furthermore, the work includes the synthesis of ZnO and TiO₂ nanoparticles via chemical methods in the high alkalinity solution. These nanoparticles were used to synthesize two novel nanocomposites named OESMBIC-ZnO and OESMBIC-TiO₂. The synthesized nanocomposites were characterized by FTIR, SEM, EDX, TEM, and XRD. The results prove that the prepared titanium oxide as nanotubes with diameters ranging between 20 and 35 nm decorated with OESMBIC. The results prove that ZnO in OESMBIC-ZnO was found as nanorods with different lengths and diameters of 40–65 nm decorated with OESMBIC molecules. The as-prepared compounds; OESMBIC, OESMBIC-ZnO, and OESMBIC-TiO₂ were used for the hydrogen storage application using the VTI method. The results prove that the addition of ZnO and TiO₂ nanoparticles enhanced the storage ability of OESMBIC as the OESMBIC gave only 0.50 wt% at an equilibrium pressure of 40 bar, while it reached 2.40 and 4.37 wt% at equilibrium pressures of 60 and 75 bar for OESMBIC-ZnO and OESMBIC-TiO₂, respectively.