In this work, taking NiSe2 as a prototype to be used as cocatalyst in photocatalytic hydrogen evolution, we demonstrate that the crystal phase of NiSe2 plays a vital role in determining the catalytic stability, rather than activity. Theoretical and experimental results indicate that the phase structure shows negligible influence to the charge transport and hydrogen adsorption capacity. When integrating with carbon nitride (CN) photocatalyst forming hybrids (m-NiSe2/CN and p-NiSe2/CN), the hybrids show comparable photocatalytic hydrogen evolution rates (3.26 µmol/h and 3.75 µmol/h). Unlike the comparable catalytic activity, we found that phase-engineered NiSe2 exhibits distinct stability, i.e., m-NiSe2 can evolve H2 steadily, but p-NiSe2 shows a significant decrease in catalytic process (~57.1% decrease in 25 h). The factor leading to different catalytic stability can be ascribed to the different surface conversion behavior during photocatalytic process, i.e., chemical structure of m-NiSe2 can be well preserved in catalytic process, but partial p-NiSe2 tends to be converted to NiOOH.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |