Ammonium carbonate

Ferric chloride (FeCl₃.6H₂O), ferrous sulfate (FeSO₄.7H₂O), Zinc acetate (ZnAc₂.2H₂O), aqueous ammonia (NH₃.H₂O) and phenol (C₆H₅OH) were obtained from Merck company and ammonium carbonate ((NH₄)2CO₃) was purchased from Daejung (South Korea) and used without further purification.

Iron (III) nitrate nonahydrate (98%), copper (Cu) (II) nitrate trihydrate (99%), aluminum nitrate nonahydrate, molybdate tetrahydrate, ammonium carbonate, hydrogen peroxide (H₂O₂, 30%), melamine (≥ 99.0%), and citric acid anhydrous (≥ 99.5%) were purchased from Daejung Chemical and Metals Co (Gyeonggi-do, Korea). Formaldehyde (37 wt% in water), sulfuric acid (95–98%), and ethyl alcohol anhydrous (99.9%) were purchased from Sigma–Aldrich (St. Louis, USA). Si nanoparticles powder (APS ≤ 50 nm, 98%) was purchased from Alfa Aesar, Inc (MA, USA). GO (0.5%) was purchased from Angstron materials (Gyeonggi-do, Korea). APTES (≥ 99%) was provided by AcroSeal (United Kingdom. All reagents of analytical grade and materials were used as received. Deionized (DI) water was used in the preparation of aqueous solutions.

Iron (III) nitrate nonahydrates (Fe(NO₃)₃·9H₂O, 98%), copper (II) nitrate trihydrates (Cu(NO₃)₂·3H₂O, 99%), aluminum nitrate nonahydrates (Al(NO₃)₃·9H₂O), ammonium molybdate tetrahydrates ((NH₄)₆Mo₇O₂₄·4H₂O), and ammonium carbonate ((NH₄)₂CO₃) were purchased from DAEJUNG CHEMICALS&METALS CO, Korea. All the reagents were of analytical grade and used as received. Silicon nanoparticles (powder, APS ≤ 50 nm, 98%) were purchased from Alfa Aesar, Inc. Graphene oxide (GO) was purchased from Angstron materials (Dayton, OH, USA N002-PS, 5.0%) and used as received. Ethyl alcohol (anhydrous, 99.9%) was purchased from Sigma-Aldrich. Deionized (DI) water (resistivity > 18 μΩ) was employed for preparing all the aqueous solutions for all the experiments.