Carbon-based hole storage engineering toward ultralow onset potential and high photocurrent density of integrated SiC photoanodes

In the present work, we report the exploration of integrated photoanode based on SiC nanohole arrays with a rationally designed amorphous carbon nanolayer. The SiC nanoarrays are fabricated via anodic oxidation, and the carbon outlayers are introduced by chemical vapor deposition (CVD) process, respectively. In such case, the active materials of carbon outlayer coated SiC nanoarrays (SiC@C) and current collector of the unetched SiC wafer are established into a whole structure without interfaces, thus favoring the formation of integrated pho-toanode. It is verified that the coated carbon nanolayer acts as an efficient hole storage layer, which effectively drives the separation of photogenerated carriers. Consequently, the as-fabricated SiC@C photoanode exhibits excellent photoelectrochemical (PEC) water splitting properties with a high solar-to-hydrogen efficiency of 2.67%. Moreover, it delivers an ultralow onset potential of-0.049 V (vs. RHE) and a high photocurrent density of 5.0 mA/cm2 (1.23 V vs. RHE), superior to those of intrinsic SiC counterparts and most SiC nanostructures ever reported, implying their promising applications in the field of solar energy conversion.

Automated summary

This research reports the exploration of an integrated photoanode based on SiC nanohole arrays with a rationally designed amorphous carbon nanolayer. The coated carbon nanolayer acts as an efficient hole storage layer, driving the separation of photogenerated carriers. The as-fabricated SiC@C photoanode exhibits excellent photoelectrochemical water splitting properties, indicating promising applications in solar energy conversion.