MoO3NPs/ZIF-8 composite material prepared via RCVD for photodegradation of dyes

Toxic wastewaters from the textile industry have made its way into rivers and other waterways, posing a serious health treat on both human and wildlife. Herein, this data set presents the potential use of MoO3 nanoparticles supported on ZIF-8 in the photodegradation of a cationic dye molecule. The data presented in this article report a concise description of experimental conditions for the spray-dried ZIF-8 synthesis and subsequent deposition of MoO3 nanoparticles via rotary chemical vapor deposition (RCVD). The photodegradation and analysis data reviled that the MoO3-NPs@ZIF-8 3 wt% displayed the ability of degrading methylene blue up to 82% and 95% after 180 and 300 min, respectively.


Specifications
Chemistry, Environmental Sciences and Engineering More specific subject area Photodegradation Type of data Table, image, graph, figure How data was acquired -Dye concentration measurement: Monitored by UV-vis absorption spectroscopy (UV-1800 Shimadzu, Japan) -Catalyst stability: Diffraction spectra were acquired using PXRD spectroscopy (Rigaku Ultima III, Japan), the molecular integrity was analyzed by FT-IR spectroscopy (Nicolet 6700, Thermo Scientific) and the morphology was confirmed by Scanning electron microscope (SEM -Phenom,

Value of the data
The use of the rotary chemical vapor deposition can encourage researchers to efficiently deposit other compounds on metal-organic frameworks.
The as-synthesized MoO 3 -NPs/ZIF-8 exhibits good photodegradation properties towards the removal of dye from polluted environment.
To understand the relationship between an alternative nanoparticle deposition technique and the subsequent properties of the composite material.

Data
Nanoparticles deposition and coating of powders have been accomplished with numerous techniques including chemical vapor deposition (CVD) [2] and sol-gel [3]. The combination of a fluidized bed and CVD has been extensively used for coating powders. However, operational limits are imposed due to particle size and density of the powders. Rotary chemical vapor deposition (RCVD) is an alternative method that allows us to remove previous operational restrictions and achieve a uniform nanoparticle deposition [4]. A schematic representation and pictures of the apparatus are reported in Figs. 1 and 2.
Due to the harmful effects of industrial dye emission to the environment and human health [5,6], the following data set demonstrate the photocatalytic potential of the as-synthesized MoO 3 -NPs/ZIF-8 on a  cationic dye molecule. In Fig. 2 is shown the structure of the methylene blue (MB). A change in maximum absorbance at 664 nm was used to monitor the dye's degradation [7]. The UV-vis spectra for the methylene blue photodegradation are illustrated in Fig. 3 (Fig. 4).
In order to assess the structural stability of the MoO 3 -NPs/ZIF-8 3 wt% after its use, the catalyst has been recycled multiple times. The PXRD spectra (Fig. 5) and FT-IR spectra (Fig. 6) reveal that the photocatalyst remains stable under the reaction condition showing negligible degradation. Furthermore, MoO 3 -NPs/ZIF-8 3 wt% morphology was characterized after the 4th cycle by SEM (Fig. 7) and the metal content was assessed by ICP-AES (Table 1). The photocatalyst has been successfully recycled four times without evident decrease in performance, as shown in Fig. 8.

Materials
All reagents and solvents were purchased from commercial sources and used without further purification. The synthesis of the catalyst MoO 3 -NPs/ZIF-8 is detailed in the original paper, ["Submitted to Microporous and Mesoporous Materials."] and are briefly discussed below.

Spray-dried ZIF-8 synthesis
The synthesis of ZIF-8 was achieved following literature procedure with minor modification [1]. Zn(OAc) 2 Á 2H 2 O (16 mmol) and 2-methylimidazole (16 mmol) are solubilized in 50 mL of methanol. The reaction mixture was spray-dried with a feed rate of 11.5 mL min À 1 , a flow rate of 4.6 Â 10 6 mL min À 1 and an inlet temperature of 180°C. The product is collected as a white powder and suspended in methanol overnight. After centrifugation the ZIF-8 is dried at 60°C in vacuum oven.

Photodegradation experiments
The photodegradation of methylene blue by MoO 3 -NPs/ZIF-8 was carried out as follows: 50 mg of as-synthesized catalyst were added into 200 mL dye aqueous solution (10 mg/L) and magnetically stirred for 30 minutes in a dark environment. Subsequently, the suspension is poured into a watercooled jacked glass reactor to dissipate the intense heat sourcing from the solar lamp (PL-XQ 350 W Xenon). The solution aliquots were filtered through a 0.22 μm Millipore filter and analyzed by UV-vis absorption spectroscopy.

Data analysis
The MoO 3 -NPs/ZIF-8 photocatalytic performance is calculated based on the methylene blue photodegradation kinetics according to Eq. (1): where C is the MB concentration at any given time (t), C 0 is the initial concentration and k is the rate constant.