Metal organic framework derived NaCoxOy for room temperature hydrogen sulfide removal

Abstract

Novel NaCoxOy adsorbents were fabricated by air calcination of (Na,Co)-organic frameworks at 700 °C. The NaCoxOy crystallized as hexagonal microsheets of 100–200 nm thickness with the presence of some polyhedral nanocrystals. The surface area was in the range of 1.15–1.90 m2 g−1. X-ray photoelectron spectroscopy (XPS) analysis confirmed Co2+ and Co3+ sites in MOFs, which were preserved in NaCoxOy. The synthesized adsorbents were studied for room-temperature H2S removal in both dry and moist conditions. NaCoxOy adsorbents were found ~ 80 times better than the MOF precursors. The maximum adsorption capacity of 168.2 mg g−1 was recorded for a 500 ppm H2S concentration flowing at a rate of 0.1 L min−1. The adsorption capacity decreased in the moist condition due to the competitive nature of water molecules for the H2S-binding sites. The PXRD analysis predicted Co3S4, CoSO4, Co3O4, and Co(OH)2 in the H2S-exposed sample. The XPS analysis confirmed the formation of sulfide, sulfur, and sulfate as the products of H2S oxidation at room temperature. The work reported here is the first study on the use of NaCoxOy type materials for H2S remediation.

From MOF-199 Microrods to CuO Nanoparticles for Room-Temperature Desulfurization: Regeneration and Repurposing Spent Adsorbents as Sustainable Approaches

“…Metal–organic frameworks (MOFs) are a unique class of inorganic–organic hybrids known for their exceptionally high surface area and porosity. These crystalline hybrid materials have found wider applications in gas separation, capture, storage, and delivery, which are associated with the flexibility and tunability of the MOF’s structure driven by organic linkers. − Apart from their direct applications in energy and the environment, − MOFs serve as templates for a range of carbonaceous and noncarbonaceous materials through pyrolysis/calcination processes. , These MOF-derived materials are of great importance in the development of highly porous and morphologically preserved materials for catalysis, gas adsorption, and sensing. − …”

Size-controlled, hollow and hierarchically porous Co2Ni2 alloy nanocubes for efficient oxygen reduction in microbial fuel cells

“…6a showed major broad peaks of Co 2p 1/2 (780.4 eV) and Co 2p 3/2 (796.1 eV), which were split into subpeaks of Co 0 (793.4 and 778.3 eV), Co 2+ (797.2 and 781.55 eV) and satellite Co (785.8 and 803.4 eV). 57,60,61 However, the binding energy of Co 0 exhibited an obvious blue shift compared to that of the pure Co HANCs, which was attributed to the variation of the electron distribution state by alloying with Ni species added. 62 The binding energy shifts of the Co 2p 3/2 subpeaks in the Co 3 Ni 1 , Co 2 Ni 2 and Co 1 Ni 3 HANCs were 0.13, 0.20, and 0.37 eV, respectively (Table S7†).…”

“…S15†) were split into subpeaks of CO (529.6 eV), low-coordinated oxygen (531.5 eV) and C–O (533.4 eV). 57–59 The Co 2p spectra in Fig. 6a showed major broad peaks of Co 2p 1/2 (780.4 eV) and Co 2p 3/2 (796.1 eV), which were split into subpeaks of Co 0 (793.4 and 778.3 eV), Co 2+ (797.2 and 781.55 eV) and satellite Co (785.8 and 803.4 eV).…”

Probing the origin and stability of bivalency in copper based porous coordination network and its application for H2S gas capture

“…The HRXPS C 1s spectrum has four peaks at 284.7, 286.7, 288.7, and 291.3 eV for C=C (69.6%), C–O/C–N (16.2%), –O–C=O (10.9%), and π–π * (3.2%), respectively, from the TATB 3− linker (Fig. 2 d) 20 , 21 . The HRXPS O 1 s spectrum has three contributions at 531.5, 532.2, and 533.5 eV for Cu–O (49.1%), C–O (32.3%), and H 2 O (18.5%), respectively (Fig.…”

“…The adsorption capacity decreased from 4.4 to 3.3 mmol g –1 with the increasing flow rate from 0.1 to 0.3 L min –1 . The negative effect of the increasing flow rate is associated with a drop in the gas retention time, which reduces the adsorbate-adsorbent interaction 20 . The effect of adsorbent loading was studied in the 60–120 mg range with a flowrate of 0.2 L min –1 (Fig.…”