Orange 2

All of the reagents used in this work were of analytical grade and were used with no further purification and are as follows: titanium(IV) isopropoxide (TTIP) (Aldrich, 97%); ethanol absolute grade (99.9%); hydrochloric acid (37%) and Orange II (Sigma Chemical Co.).

Cellulose (Baikal Cellulose and Paper Mill, Baikalsk, Russia) had a polymerization degree of 600 and contained 92% alpha-cellulose and less than 6% water. [EMIM]Ac, [EMIM]Cl, and [BMIM]Ac (Sigma-Aldrich, Steinheim, Germany) were used as ionic solvents, which were diluted with DMSO (Sigma-Aldrich) as a nominal co-solvent of cellulose. Non-woven polyester fabric (Crane Technical Materials, Pittsfield, MA, USA), which had a density of 87 g/m², a thickness of 90–99 μm, and an air permeability of 16.0–29.6 cm·s⁻¹·Pa⁻¹, was used as a micro-porous substrate for impregnating with cellulose solution and subsequent production of cellulose nanofiltration membranes. Distilled water, methanol, ethanol, and isopropanol (Himmed, Moscow, Russia) were used as non-solvents (precipitants), while hexane (Himmed) was applied for the post-processing of formed membranes. The transport properties of obtained cellulose membranes were investigated by using DMF (Sigma-Aldrich) with dissolved dyes Orange II (350 g/mol, Sigma-Aldrich) and Remazol Brilliant Blue R (626 g/mol, Sigma-Aldrich). All reagents were chemically pure and used without additional purification.

2-aminothiophenol (2-ATP; Sigma Aldrich, purity, 99.5%) and nitrobenzene (NB; Sigma Aldrich, purity, 99.0%), Orange II (Sigma Aldrich, purity, 99.5%), methylene blue (Sigma Aldrich, purity, 99.5%), carbon monoxide (CO, 99.95%) and molecular oxygen (O₂, 99.99%) gas were purified by turbo-pumping to remove impurities prior to dosing onto the GO, rGO, and graphene samples grown on silicon substrates. A direct dozer, controlled by using a variable leak valve, was used to dose the substrates.

Sodium acetate (99%), KH₂PO₄ (ACS reagent, ≥99.0%), reagent grade NaOCl solution
(available chlorine, 10–15%), and Orange II (certified) were
purchased from Sigma-Aldrich. Acetic acid (glacial), Na₂HPO₄ (anhydrous, enzyme grade), and water (HPLC grade,
submicrometer-filtered) were obtained from Fisher Scientific. Na₃PO₄·12H₂O was purchased from Acros
Organics. Hydrogen peroxide (30%) stabilized by sodium stannate was
obtained from VWR Chemicals. Fe-TAML 2 synthesized as
previously described^{3 (link)} was provided by SUDOC.²³ Complexes 1a and 1b were obtained from old stocks at IGS (Institute of Green Science).
All the Fe-TAMLs used for kinetic measurements were purified by passing
through C-18 silica gel with water as an eluent. Orange II was recrystallized
from an ethanol/water mixture by adding H₂O dropwise to
its solution in warm ethanol. Other above-mentioned chemicals were
used without further purification.