MoS2 hydrogen evolution catalysis on p-Si nanorod photocathodes

• Published in: Materials science in semiconductor processing Vol. 121; p. 105308
• Main Authors: Dang, Tran Chien, Dang, Van Thai, Nguyen, Tien Dai, Truong, Thi Hien, Man, Minh Tan, Bui, Thi Thu Hien, Tran, Thi Kim Chi, Tran, Dai Lam, Truong, Phuong Dung, Nguyen, Cao Khang, Nguyen, Viet Chien, Seo, Dong-Bum, Kim, Eui-Tae
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2021
• Subjects: Heterojunction; MoS2; Photoelectrochemical; Si nanorod; Si nanorod; MoS2; Photoelectrochemical; Heterojunction
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2020.105308

We report on the synthesis of few−layers MoS2 flakes coated on the p−Si nanorods (p−SiNRs) via the metalorganic chemical vapor deposition (MOCVD) method. The MoS2 flakes show a vertically−standing, few−layers (10–15) morphology. The photoluminescence characteristic of the MoS2/p−SiNRs heterojunction exhibits a blue−shift energy bandgap (1.65−1.78 eV) at temperature of 77 K with thinner MoS2 layers due to the quantum confinement effect. As a result, the fabricated MoS2/p−SiNRs photocathode results in a saturated photocurrent density (PCD) and a photoconversion efficiency (η) of 42.3 mA cm−2, and 0.64% at 0 V (vs. RHE), respectively. Due to the built−in potential of heterojunction and more active edge sites, the onset voltage of the MoS2/p−SiNRs sample was positively shifted to ~0.72 V (vs. RHE). Based on this finding, we suggest that a heterojunction structure might serve an approach for fabricating the hybrid photoelectrochemical (PEC) device of the Si−based material. [Display omitted] •Vertical-standing few-layer MoS2/p- Si nanorods were synthesized by the chemical etching, and CVD methods.•Photocurrent density and photoconversion efficiency of MoS2/p-Si nanorod-based photoelectrochemical cell (PEC) obtains 42.3 mA.cm-2, and 0.64%, respectively•The PEC device exhibits a positive onset potential of 0.72 V (vs. RHE) and the saturation current density is close to the JSC of the ideal solar cell.