▎ 摘　　要

NOVELTY - Adsorbent comprises a sulfur-doped porous reduced graphene oxide comprising 9.57-10.42% sulfur, pore size of 3-80 nm and a surface area of 438-465 m2/g. USE - The adsorbent is useful for removing mercury(II) from water (claimed). ADVANTAGE - The adsorbent: is cheap, economical, eco-friendly and reduces multiple times using simple regeneration procedure; has high adsorption capacity and high rate of adsorption; and provides level of mercury in water after purification with the adsorbent is below the world health organization limit. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing (P1) the adsorbent comprising (i) oxidation of graphene to graphene oxide (GO), mixing graphene oxide of step (i) in the presence of dibenzyl disulfide (BDS) and silica template, where the ratio of BDS:GO:silica template is 5:1:5:25, thermal annealing of the mixture of step (ii) at a controlled temperature of 800-900 degrees C for a duration of 4.5-5 hours under inert atmosphere, and hydrofluoric acid etching of the annealed mixture of step (iii) to obtain the sulfur-doped porous reduced graphene oxide based adsorbent; (2) removing (P2) mercury (Hg(II)) from water comprising (a) packing of the sulfur-doped porous reduced graphene oxide adsorbent in a mercury decontamination column, (b) placing the mercury decontamination column of step (a) in contact with mercury-contaminated water, where the mercury decontamination column adsorbs the mercury from the mercury-contaminated water, (c) discharging the purified mercury-decontaminated water, and (d) removing adsorbed mercury from the mercury decontamination column and regenerating the column; and (3) device comprising the mercury decontamination column packed with sulfur-doped porous reduced graphene oxide based adsorbent.