Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 27th March 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 5, 2016
Previous Article Next Article

Adsorption of III/V ions (In(III), Ga(III) and As(V)) onto SiO2, CeO2 and Al2O3 nanoparticles used in the semiconductor industry

Author affiliations

Abstract

The semiconductor industry annually uses thousands of tons of nanoparticles (NPs) in chemical mechanical polishing (CMP) processes. When III/V materials are processed with CMP, the NPs and In(III), Ga(III) and As(V) ions (i.e., III/V ions) coincide and end up in wastewater from electronics fabrication lines. CMP NPs (colloidal SiO2 (C-SiO2), fumed SiO2 (F-SiO2), CeO2 and Al2O3) may interact with III/V ions (e.g. In(III), Ga(III) and As(V)) and facilitate their transport in aquatic systems. Across a range of pH levels, we found that appreciable adsorptions of In(III) ions onto CeO2 or Al2O3 NPs, Ga(III) ions onto C-SiO2, F-SiO2, CeO2 or Al2O3 NPs, and As(V) ions onto CeO2 or Al2O3 NPs occur. We determined the intrinsic surface complexation constant (KC,intr) between the ions and NPs by fitting the experimental data with a surface complexation model (SCM). We then extended the SCM to calculate adsorption as a function of NP size. As size increases, surface site density (SSD) increases, whereas specific surface area (SSA) decreases; both eventually reach a plateau where the bulk material stands. Nonetheless, mass site density (MSD), i.e. the site number per mass, increases with size reduction, indicating that smaller particles give higher adsorption capacity based on the same mass. Upon a 1 nm size reduction of C-SiO2 NPs, the model predicts that the MSD increases <1% for sizes >100 nm and >10% for sizes <10 nm. For C-SiO2 NPs adsorbing Ga(III) ions, the model predicts that decreasing the NP size enhances the adsorption efficiency the most in the pH ranges of 2.5–3 and 8.5–11. This work represents the first SCM capable of incorporating size-dependent NP properties to predict adsorption of environmentally relevant ions.

Graphical abstract: Adsorption of iii/v ions (In(iii), Ga(iii) and As(v)) onto SiO2, CeO2 and Al2O3 nanoparticles used in the semiconductor industry

Back to tab navigation

Supplementary files

Publication details

The article was received on 19 Jun 2016, accepted on 25 Aug 2016 and first published on 30 Aug 2016


Article type: Paper
DOI: 10.1039/C6EN00184J
Citation: Environ. Sci.: Nano, 2016,3, 1014-1026

  •   Request permissions

    Adsorption of III/V ions (In(III), Ga(III) and As(V)) onto SiO2, CeO2 and Al2O3 nanoparticles used in the semiconductor industry

    X. Bi and P. Westerhoff, Environ. Sci.: Nano, 2016, 3, 1014
    DOI: 10.1039/C6EN00184J

Search articles by author

Spotlight

Advertisements