A general route to modify diatomite with niobates for versatile applications of heavy metal removal

Abstract

A general solution-phase strategy is developed to synthesize nanostructure niobates such as MnNb 2 O 6 , SnNb 2 O 6 and ZnNb 2 O 6 on natural mineral diatomite for water environmental remediation. (NH 4 ) 2 C 2 O 4 aqueous solution is the key to achieve a scalable and controllable synthesis of niobate/diatomite hybrid systems, which generates NH 3 $H 2 O for surface etching activation of diatomite, and H 2 C 2 O 4 for complexation dissolution of Nb 2 O 5 , enabling the heterogeneous crystallization process to proceed with controllable growth kinetics. First principle calculations indicate that both niobium atom and niobiumoxygen species have the lowest adsorption energy on SiO 2 surface, and then induce the nucleating process of Nb-O-Mn (or Zn, Sn) networks. Cr(VI), Fe(III), and Pb(II) ions are taken as target pollutants to evaluate the water-cleaning ability of the niobate-modified diatomite. Possible mechanisms for the photoreduction of Cr(VI), physical adsorption of Fe(OH) 3 colloids, and chemisorption of Pb(II) ions are proposed on the basis of experimentally investigations. The possibility of combining the advantages of natural mineral diatomite and nanostructured niobates provides a highly robust and potential material system with versatile functionalities of heavy metal ion removal, demonstrating great promise for a wide range of water purification.

Recent advances of silicate materials for wastewater treatment: a review

“…Based on the characteristics of diatomite, our research group has developed a series of diatomite-based composites, broadening their applications in sewage purification. Employing a universal synthesis approach, the solution-phase route was developed by Wu et al (2019) to synthesize nanostructured niobates on natural mineral diatomite (figures 10(a)-(c)) [141]. Interestingly, the system of niobates@diatomite can be adjusted using for the photoreduction of Cr(VI) to Cr(III), the physical eliminating Fe(III), and the direct chemisorption of Pb(II).…”

Influence of diatomite and its base modifications on the self-adhesive properties of silicone pressure-sensitive adhesives

“…Wang, Yang et al modified the diatomite by easy alkaline treatment. The crude diatomite was dispersed in NaOH solution at 90 °C while stirring for 2 h. After separation, the modified diatomite was washed several times with water and anhydrous ethanol until a pH value close to neutral was obtained 14 .…”

“…The next step was drying at room temperature to an air-dry state. Thermal activation was carried out by annealing the native, pre-washed and sieved diatomite in a muffle furnace for 3 h at 440–460°C 14 .…”

A POSS‐Phosphazene Based Porous Material for Adsorption of Metal Ions from Water

“…In the past, extensive studies have been reported to unravel the scopeo fs uch functional materials as activated porous carbon, [5] zeolites, [6] silica particles, [7][8][9][10][11][12][13] graphene oxide, [14,15] metals or metal oxides, [16,17] natural minerals [18][19][20] etc. as adsorbents for remediationo fm etal ions from water.T he search for new and efficient adsorbentsh as prompted the design and synthesis of functional polymers, [21][22][23][24][25][26][27] metal organic frameworks, [28][29][30] polymeric composites [31][32][33] and biohybrids.…”