Authors: Xiwen Zhang, Sajeev John
Published: 2025-03-17
Source: Full article
AbstractThe immense challenge of large‐scale implementation of photoelectrochemical (PEC) water splitting and carbon fixation lies in the need for a cheap, durable, and efficacious photocatalyst. Cubic silicon carbide (3C‐SiC) holds compelling potential due to its auspicious band positions and high‐volume, high‐quality, single crystal industrial manufacturing, but is hindered by its inferior light absorptivity and anodic instability. A slanted parabolic pore photonic crystal (spbPore PC) architecture with graphitic carbon nitride (g‐CN), nickel(II) oxide (NiO), or 6H silicon carbide protective coatings is proposed to overcome the drawbacks of 3C‐SiC photoelectrodes. A 30 µm‐ and 62 µm‐thick 3C‐SiC spbPore PC of lattice constant 0.8 µm demonstrates maximum achievable photocurrent density (MAPD) of 9.95 and 11.53 mA cm−2 in the [280.5, 600] nm region, respectively, representing 75.7% and 87.7% of the total available solar photocurrent density in this spectral range. A 50 nm‐thick g‐CN or NiO coating forms type‐II heterojunctions with the 3C‐SiC spbPore PC, facilitating the charge transport and enhancing the corrosion resistivity, all together demonstrating the MAPD of 9.81 and 10.06 mA cm−2, respectively, for 30 µm‐thick PC. The scheme advances the low‐cost, sustainable, real‐world deployment of PEC cells for green solar fuel production.