Synthesis of Titanium Dioxide/Silicon Dioxide from Beach Sand as Photocatalyst for Cr and Pb Remediation

Abstract

Heavy metals are non-biodegradable and have a high toxicity effect to living things which makes their presence in the environment extremely dangerous. The method of handling heavy metals waste by photocatalysis techniques using TiO2/SiO2 composite showed a good performance in reducing harmful pollutants. In this study, SiO2 from Bengkulu beach sand was used as a support material for TiO2 photocatalyst to reduce Cr(VI) and Pb(II) concentrations. SiO2 was obtained through leaching techniques using NaOH as a solvent. The TiO2/SiO2 composite photocatalyst were synthesized using a solvothermal method at 130 °C and then characterized using XRD, FTIR, SEM and PSA. Based on the XRD diffractogram, the synthesized TiO2 showed the anatase structure while the SiO2 showed the amorphous structure. Ti-O-Si bond is defined in the IR spectra, which indicates that the relationship between TiO2 and SiO2 is a chemical interaction. The results of SEM and PSA characterizations show agglomerated spherical (round) particles with a mean particle size of 616.9 nm. The TiO2/SiO2 composite of 7:1 ratio showed the highest photocatalytic activity after 180 minutes of UV irradiation, with a concentration-decrease percentage of 93.77% and 93.55% for for Cr(VI) and Pb(II), respectively.

Recent Improvement Strategies on Metal-Organic Frameworks as Adsorbent, Catalyst, and Membrane for Wastewater Treatment

“…Alternatively, combining two materials to create a composite system has been receiving major attention in catalysis. In this scenario, one material will act as a structural support for anchoring the catalytically active second material in order to enhance its stability and ensuring reusability [ 82 ]. Huge efforts to combine MOFs with other functional materials in order to enhance its catalytic properties have been attempted, which can be confined inside the MOFs’ structure thanks to its permanent porosity [ 83 , 84 ].…”

Synthesizing and Evaluating the Photocatalytic and Antibacterial Ability of TiO2/SiO2 Nanocomposite for Silicate Coating

“…I A and I R represent the integral intensity of diffraction peaks on the crystal surface of anatase (101) at 2θ 25.2°and rutile (110) at 2θ 27.6°, respectively. The anatase and rutile grain size of TiO 2 /SiO 2 Nc were calculated using the Debye-Scherrer formula (Diana et al, 2020):…”

“…Previous studies on mesoporous silica nanospheres and nanotubes functionalized with titanium dioxide have demonstrated strong enhancement of titanium dioxide photocatalytic performance (Sikora et al, 2017). Moreover, there are also several reported on TiO 2 /SiO 2 nanocomposite (Nc) material that has shown increases in the specific surface area, porosity, thermal stability, mechanical, antibacterial, and photocatalytic performance (Nilchi et al, 2010;He et al, 2019;Tien et al, 2019;Diana et al, 2020;Pham et al, 2020).…”

Photocatalysis of nanocomposite titania–natural silica as antibacterial against Staphylococcus aureus and Pseudomonas aeruginosa

“…30 SiO 2 is obtained through synthesis or extraction from natural materials, both biological and non-biological. 23 To maximize natural resources, silica is obtained from the extraction of beach sand. 31 Based on data from the Ministry of Energy and Mineral Resources, Indonesian Geological Resources Center (2012), the total availability of silica sand is approximately 22.5 billion tons spread throughout Indonesia with 85% of the highest distribution on Sumatra Island, including Bengkulu Province.…”

“…Furthermore, the anatase phase of TiO 2 has energy corresponding to the reduction energy of O 2 in the photocatalytic process, 22 but its transformation to rutile limits the photocatalytic activity. 23 Also, TiO 2 has some drawbacks, such as agglomeration, which causes a reduction in surface area in solution. 24,25 However, this reduction is minimized by combining TiO 2 with other materials such as SiO 2 , 23 ZnO, 26 Fe 2 O 3 , 27 and CuO.…”