Photocatalytic NH^sub 3^versus H^sub 2^ evolution over g-C^sub 3^N^sub 4^/Cs^sub x^WO^sub 3^: O^sub 2^ and methanol tipping the scale

• Published in: Applied catalysis. B, Environmental Environmental, 2018-11, Vol.235, p.197
• Main Authors: Shi, Anye, Li, Huihui, Yin, Shu, Hou, Zaili, Rong, Jiayue, Zhang, Jiachi, Wang, Yuhua
• Format: Article
• Language: English
• Subjects: Ammonia; Carbon nitride; Catalysis; Chemical synthesis; Electrons; Evolution; Excitation spectra; Hydrogen evolution; Hydrogen production; Irradiation; Light irradiation; Methanol; Nanorods; Near infrared radiation; Nitrogen; Oxidation; Oxygen; Photocatalysis; Photocatalysts; Ultraviolet radiation; Water splitting
• ISSN: 0926-3373; 1873-3883

CsxWO3 nanorods can be used to sensitize the single layer g-C3N4, where full spectrum light harvesting excited electrons to drive the photocatalytic reduction of N2 into NH3. Under UV light, both water splitting and solar ammonia synthesis reaction exhibit high activity. However, selectivity towards ammonia over hydrogen is realized under NIR irradiation. With the control of methanol, O2 can directly decide the NH3 or H2 evolution on photocatalyst. The origin is the strong capture of O2 with the electrons from the photocatalyst under light irradiation to yield the oxygen active species, which transfer electrons subsequently with help of methanol to generate NH3. However, H2 production will be suppressed by O2. And with its sacrifice, methanol preserves the produced NH3 from oxidation. The O2-sacrificial agent mediated NH3 evolution reaction found here provides insights in the promotion role of them in other catalysis.