Standard operating procedure for benchmarking and performance evaluation of graphene oxide membranes

With many studies reporting high water flux and strong solute rejection, graphene oxide membranes (GOMs) show clear potential. Motivated by these findings, we establish a standard operating protocol (SOP) for the reliable and reproducible evaluation of GOM performance. Our procedure begins with permeability measurements of a blank large-pore polymer template, followed by incremental GO deposition to track performance changes. We found that the polymer template, even with only half-coverage of GO, showed a significant drop in water flux. We identify a minimum GO thickness of approximately 140 nm on the polymer template with 47 mm diameter is necessary to achieve complete GO coverage and ensure reliable membrane performance with a water flux of ~100 LMH bar −1 and dye removal of ~70 %. Similar behaviors are also observed in the hollow fibre (HF) membrane system, indicating the importance of such practices in industrial applications. Together, these results provide a reliable procedure for benchmarking GOMs and for guiding their translation from laboratory studies to industrial operation. Recent reports on very high-water flux and high rejection rates for graphene oxide membranes (GOMs) prompted us to develop good practices for performance measurements. Our systematic study shows that incomplete GO coverage on the substrate can result in overestimated or erroneous water flux values, suggesting the importance of standard work procedures (SOP) for GOM performance evaluations. • Incomplete GO coverage on the substrate results in overestimated water flux values. • GO thickness ~140 nm on flat and hollow-fibre polymer template ensures complete coverage. • 140 nm GO coating provides reliable water flux ~100 LMH/bar and dye removal ~70 %.