Hydroxyapatite nanoparticles decorated with metal–organic framework, Co‐Cu/ZIF@HAp, and evaluation of photocatalytic performance of the prepared nanocomposite in the degradation of organic pollutants

Abstract

In this study, a novel hydroxyapatite (HAp)‐based composite, Co‐Cu/ZIF@HAp, was constructed through in situ growth and simultaneous sonication followed by magnetic string. Herein, the HAp‐based nanocomposite was obtained in which HAp was coated with cobalt–copper bimetallic zeolitic imidazolate framework (ZIF) in one‐pot synthesis method. The as‐synthesized composite was characterized by PXRD, FTIR, FE‐SEM, EDS, HR‐TEM, TGA‐DTG, XPS, BET, and UV‐DRS techniques, which suggested that HAp was well coated with bimetallic ZIF. The prepared composite was utilized as a catalyst in degradation of organic pollutants. Removal of organic pollutants such as organic dyes has become indispensable due to their higher stability, toxicity, and mutagenic nature. Two commonly found organic dyes, namely, Eosin Yellow (EY) and Brilliant Green (BG), were chosen for the investigation of photocatalytic activity of the as‐prepared catalyst. The degradation process was carried out under solar radiation, and there was no utilization of any oxidizing and reducing agent. Several parameters such as amount of catalyst dose, initial concentration of the dye solution, and effect of different pH conditions were evaluated for better understanding of photocatalytic performance of Co‐Cu/ZIF@HAp composite. Both EY and BG dyes were almost degraded up to 98.3% and 99.5%, respectively, within 50 min by the as‐prepared nanocomposite. Also, quenching test was performed that confirmed the formation of superoxide radicals (O2−.) as reactive oxygen species (ROS) in the photodegradation process. The as‐synthesized catalyst was repeatedly used for five times to ascertain the stability and reusability of catalyst.

Designing of a novel heterogeneous nanocatalyst ZIF-4@HAp for solvent free base catalyzed esterification reaction

“…The peaks at 3440 cm −1 and 1620 cm −1 corresponded to the stretching and bending vibrations, respectively, which were obtained because of the water molecule on the surface of the sample. 40 The FT-IR spectrum of pure hydroxyapatite is included in Fig. S1 †…”

“…HAp nanoparticles were prepared by employing a hydrothermal technique. 40 At first, two separate solutions of calcium nitrate and ammonium dihydrogen phosphate were prepared in distilled H 2 O maintaining the Ca/P molar ratio at 1.67. Then, 0.1 g of surfactant cetyltrimethylammonium bromide (CTAB) was added to the solution of Ca(NO 3 ) 2 •4H 2 O and the obtained solution was stirred at 400 rpm.…”

Metal–organic framework‐supported hydroxyapatite (UiO‐66@HAp): an efficient catalyst for the microwave‐assisted transesterification of palm oil

“…Deconvolution of HR-XPS spectra of P2p revealed two intense peaks at 132.18 eV and 133.10 eV, which correspond to P 2p 3/2 and P 2p 1/2 , respectively. 47 This suggests that the UiO-66 framework is successfully impregnated into the HAp lattice. The surface atomic abundance data obtained from the XPS results are given in Table 1.…”

CuWO4 Reinforced Co‐doped HAp Nanocomposite: Improved Photocatalytic Activity Towards Degradation of Eosin Y and Catalytic Activity in Crossed Aldol Condensation Reaction

“…Figure 3a shows the HR-XPS scan of Ca 2p and it shows two intense peaks at 347.25 eV and 350.75 eV which can be assigned as Ca 2p 3/2 and Ca 2p 1/2 respectively. [34] The peak associated with 350.75 eV and 347.25 eV can be attributed to calcium apatite and CaÀ O respectively. Deconvulation of HR-XPS scan of O 1s shows two distinct peaks at 532 eV and 531 eV which corresponds to the binding energies of OH and PÀ O bonds of PO 4 3À moieties respectively (Figure 3b).…”