Automated electrochemical synthesis was used to create combinatorial libraries of mesoporous materials using tri-block copolymers as structure directing agents (SDA). An example library of 56 ZnO samples was synthesized, varying concentrations (0-15 wt.-%) of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) - EO20 PO70EO20. High-throughput photoelectrochemical screening for the measurement of water-splitting photocatalysis identified peak performance at 3 wt.-% of the SDA. Lamellar structures and disordered mesopores were observed by TEM and XRD.