本研究製備出高活性的氮化碳觸媒，將其混合在三乙醇胺水溶液下，以可見光照射即可將水分解產氫，首先，將尿素與氯化銨的混合物煅燒，可得到氮化碳，接著再將其與乙醇分子混合後進行高溫處理，即可得到芳香環類之碳摻雜入氮化碳，利用X-Ray射線光電子能譜儀、傅立葉轉換紅外線吸收光譜及碳-13核磁共振分析來進行結構的鑑定，可證明出將乙醇分子進行熱處理可在氮化碳上接合芳香多環，而光激發螢光光譜及電子順磁共振光譜的分析結果顯示出在氮化碳上接合芳香多環能延伸π共軛系統，使得能隙變小並加速光生電荷的分離，另外，在高溫處理下，接合上芳香多環亦能保持其結晶結構，並能抑制缺陷區域的光生電荷再結合，此芳香環類之碳摻雜氮化碳能有效的將水分解產生氫氣，在420及550 nm的單光下照射，其量子效率分別為14 %及2.2 %，而以尿素為前驅物的氮化碳卻只有3.4 %及0.1 %，利用此延伸π共軛系統的新合成方法對於增加氮化碳光觸媒的活性，在未來的前景是相當被看好的。

This study details the synthesis of high-activity g-C3N4 catalysts for H2 generation from a triethanolamine aqueous solution under visible light. We anneal a mixture of urea and NH4Cl to obtain g-C3N4 nanosheets, which are subsequently solvated with ethanol molecules and annealed to form aromatic carbon-doped g-C3N4. The results of analyses conducted using X-ray photoelectron, Fourier-transform infrared, and 13carbon-13 nuclear magnetic resonance spectroscopies demonstrated that annealing the ethanol molecules leads to the grafting of aromatic heterocycles on the g-C3N4 nanosheets. The results of photoluminescence and electron paramagnetic resonance measurements reveal that the grafted aromatic heterocycles extend the π-conjugation system in g-C3N4 to reduce the band gap and facilitate the separation of photogenerated charges. The grafted aromatic heterocycles also preserve the crystallinity of g-C3N4 during high-temperature annealing, which facilitates the suppression of the recombination of photogenerated charges at defect sites. The developed aromatic carbon-doped g-C3N4 effectively catalyzes H2 generation from water decomposition, achieving apparent quantum yields of 14% and 2.2% under 420- and 550-nm monochromatic irradiation, respectively, whereas urea-derived g-C3N4 reached only 3.4% and 0.1%. The proposed strategy of extending the π-conjugation system is promising for promoting the activity of carbon-nitride photocatalysts.

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