Insight into the Crucial Factors for Photochemical Deposition of Cobalt Cocatalysts on g‑C<sub>3</sub>N<sub>4</sub> Photocatalysts Na Zhao Linggang Kong Yuming Dong Guangli Wang Xiuming Wu Pingping Jiang 10.1021/acsami.8b01590.s001 https://acs.figshare.com/articles/journal_contribution/Insight_into_the_Crucial_Factors_for_Photochemical_Deposition_of_Cobalt_Cocatalysts_on_g_C_sub_3_sub_N_sub_4_sub_Photocatalysts/5965168 Photochemical preparation of inexpensive hydrogen evolution cocatalysts is of great significance and is challenging. Currently, the crucial factors in the photochemical preparation of nonnoble metals are still unknown. In this work, taking Co/g-C<sub>3</sub>N<sub>4</sub> composite photocatalysts as a case, complexing agents and sacrificial agents were found to be the crucial factors for the photochemical deposition process. Cobalt was supported on the electron outlet points of g-C<sub>3</sub>N<sub>4</sub> for 1 h, and the ratio of Co in the Co/g-C<sub>3</sub>N<sub>4</sub> composite photocatalyst can be regulated by changing the irradiation time of the preparation process. The optimized hydrogen evolution rate of Co/g-C<sub>3</sub>N<sub>4</sub> was about 11.48 μmol h<sup>–1</sup>, which was 75 times more than pure g-C<sub>3</sub>N<sub>4</sub>. The photocatalytic H<sub>2</sub> evolution rate was stable after 48 h. The mechanism for the high activity of Co/g-C<sub>3</sub>N<sub>4</sub> composites was explored by surface photovoltage spectra and photoluminescence spectra. Co effectively promoted the separation of the photogenerated electrons and holes of g-C<sub>3</sub>N<sub>4</sub> and improved the H<sub>2</sub> production rate. 2018-02-27 00:00:00 photocatalytic H 2 evolution rate irradiation time photogenerated electrons 75 times preparation process H 2 production rate Cobalt Cocatalysts Photochemical Deposition deposition process 48 h hydrogen evolution cocatalysts nonnoble metals g-C 3 N 4 complexing agents photoluminescence spectra Crucial Factors surface photovoltage spectra 1 h electron outlet points optimized hydrogen evolution rate