Crystal‐Face Tailored Graphitic Carbon Nitride Films for High‐Performance Photoelectrochemical Cells

Graphitic carbon nitride (g‐CN) has been widely studied as a promising candidate for water splitting, owing to its metal‐free nature, moderate band gap, and low cost. However, its photocurrent density is still very low for photoelectrochemical cell applications. In this work, a crystal face tailored g‐CN photoelectrode has been fabricated by a facile thermal vapor deposition method. We use the melamine formaldehyde resin as a new precursor and have successfully fabricated g‐CN films. The intensity ratio between two typical peaks (100) and (001) of g‐CN is very different from that in the existing literature. The water splitting photocurrent density is as high as 228.2 μA cm−2, which is 126.8 times higher than pure g‐CN (1.8 μA cm−2) at 1.23 V vs. reversible hydrogen electrodes under one sun illumination without sacrificial reagents and co‐catalysts. The electrode shows the best performance, compared with the previously reported g‐CN photoelectrodes. Tailored performance: A crystal‐face tailored graphitic carbon nitride (g‐CN) film was fabricated with the combination of monomer tailoring and sulfur doping strategies. The resulting photo‐responsive current density is as high as 228.2 μA cm−2 in the absence of co‐catalysts and sacrificial reagents, showing the best performance compared with previously reported g‐CN photoelectrodes.