Preparation and application of metal ion-doped CoMgAl-hydrotalcite visible-light-driven photocatalyst

Abstract

Preparation and application of CoMgAl-hydrotalcites have been studied. In this paper CoMgAl-LDHs photocatalysts were prepared by co-precipitation. Various techniques such as UV-visible spectrometry (UV-vis), BET, differential thermal gravimetric analysis, scanning electron microscopy analysis and X-ray diffraction were used to investigate the catalytic activity, structure, and composition of the prepared samples. The photocatalysts were developed as layered double hydroxides (LDHs) due to their layered structure with OH −. In the paper, specific surface area, thermal stability, absorption of visible light, and layered structure (crystal phase) were characterized by nitrogen adsorption-desorption method, differential thermal gravimetric analysis, UV-vis methods and X-rays diffraction. The results indicated that CoMgAl-LDHs caused photocatalytic degradation of methyl orange, rhodamine talcum, and methylene blue. Initially 1 g/L of the photocatalyst was used to degrade 40 mg/L of methyl orange, it was observed that 85.7% of the methyl orange was degraded at an illumination time of 300 min. However, the degradation of rhodamine and methylene blue was not good and did not give better results as that of methyl orange.

Preparation of the Hybrids of Hydrotalcites and Chitosan by Urea Method and Their Antimicrobial Activities

“…As can be seen from Figure 8b, the U-LDH 5 thermal decomposition process is divided into three stages [46,47], between 247~300 °C for the first phase of weight loss, which is due to the removal of water from the interlayer and the physical adsorption surface [48]. At this step, U-LDH 5 remained a layered structure.…”

ZnAl–LDH/MOF-5 heterostructure nanocomposite for photocatalytic degradation of organic dyes under sunlight irradiation

“…The synthesized ZnAl–LDH/MOF-5 nanocomposite photocatalyst shows enhanced photocatalytic degradation efficiencies compared to the standard photocatalyst TiO 2 , reported LDH or MOF based photocatalysts, as shown in Table 1. 40–47…”

“…The synthesized ZnAl-LDH/MOF-5 nanocomposite photocatalyst shows enhanced photocatalytic degradation efficiencies compared to the standard photocatalyst TiO 2 , reported LDH or MOF based photocatalysts, as shown in Table 1. [40][41][42][43][44][45][46][47] A plausible mechanism of the photocatalytic dye degradation reaction of the anionic dyes by the ZnAl-LDH/MOF-5 nanocomposite is represented in Fig. 11.…”

Enhanced Adsorption, Photocatalytic Degradation Efficiency of Phenol Red Using CuZnAl Hydrotalcite Synthesized by Co-Precipitation Technique

“…Hydrotalcite materials have the formula of Mg 0.667 Al 0.333 (OH) 2 (CO 3 ) 0.167 (H 2 O) 0.5 in the natural minerals. Many different layered double hydroxides and hydrotalcite materials have successfully synthesized for their applications [1,[7][8][9][10][11]. Besides MgAlCO 3 hydrotalcites, ZnAlCO 3 materials-such as hydrotalcites-are also interesting to scientists [4,5,[11][12][13][14].…”

“…The results showed that these synthesized materials are capable of effectively decomposing sustainable organic compounds and dyes in water. However, some limitations remained, including (the first) the poor adsorption capacity of these materials for dyes, especially cationic dyes, (the second) the high processing costs due to the use of expensive and power-consuming equipment such as UV [3,9], Xenon [5,10,15], and halogen [16] lamps as irradiation lights, and (the third) only survey on the low concentration of dyes.…”