A simple, straightforward growth method for polymeric carbon nitride (CN) layers on a conductive substrate, with excellent photoelectrochemical activity, owing to the formation of a type-II heterojunction by combining two distinct chemical growth methods, is reported. The first layer consists of CN prepared from the calcination of a melem–melamine (MeM) adduct; the utilization of MeM enables the preparation of a processable paste, which can be easily cast on the conductive substrate. To prepare the second layer, melamine vapor is introduced during calcination. After calcination, two well-connected CN layers with different electronic properties are formed, leading to the formation of a type-II heterojunction. The new CN films exhibit excellent photoelectrochemical properties with a photocurrent density of up to 383 μA cm^–2 at 1.23 V versus reversible hydrogen electrode as well as an acceptable stability over 9 h in 10% (v/v) TEOA-containing 0.1 M KOH aqueous solution, thanks to the enhanced charge separation under illumination. Moreover, the CN films demonstrate good photoelectrochemical activity over a wide pH range, with photocurrent densities of 133, 80, and 118 μA cm^–2 in 0.1 M KOH, 0.1 M Na₂SO₄, and 0.5 M H₂SO₄ aqueous solutions in the absence of any sacrificial agent, respectively.

中文翻译：

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用于高效光电化学电池的具有II型异质结的氮化碳薄膜的可控合成

据报道，由于结合了两种不同的化学生长方法，形成了II型异质结，因此具有优异的光电化学活性的导电衬底上的聚合氮化碳（CN）层的简单，直接的生长方法已被报道。第一层由由梅勒-三聚氰胺（MeM）加合物煅烧制得的CN组成；利用MeM可以制备可加工的浆料，该浆料可轻松浇铸在导电基材上。为了制备第二层，在煅烧期间引入三聚氰胺蒸气。煅烧后，形成两个具有不同电子特性的良好连接的CN层，导致形成II型异质结。新的CN膜具有出色的光电化学性能，光电流密度高达383μAcm ^–2相对于可逆氢电极在1.23 V电压下，以及在10％（v / v）含TEOA的0.1 M KOH水溶液中在9小时内的可接受的稳定性，这归功于光照下电荷分离的增强。此外，CN膜在宽pH范围内显示出良好的光电化学活性，在0.1 M KOH，0.1 M Na ₂ SO ₄和0.5 MH ₂ SO ₄水溶液中，光电流密度分别为133、80和118μAcm ^–2。分别没有任何牺牲剂。