Ultrathin MoS2-coated Ag@Si nanosphere arrays as an efficient and stable photocathode for solar-driven hydrogen production

Qingwei Zhou; Shaoqiang Su; Die Hu; Lin Lin; Zhibo Yan; Xingsen Gao; Zhang Zhang; Jun-Ming Liu

doi:10.1088/1361-6528/aaa48c

Ultrathin MoS₂-coated Ag@Si nanosphere arrays as an efficient and stable photocathode for solar-driven hydrogen production

Nanotechnology. 2018 Mar 9;29(10):105402. doi: 10.1088/1361-6528/aaa48c.

Authors

Qingwei Zhou¹, Shaoqiang Su, Die Hu, Lin Lin, Zhibo Yan, Xingsen Gao, Zhang Zhang, Jun-Ming Liu

Affiliation

¹ Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, People's Republic of China.

PMID: 29381478
DOI: 10.1088/1361-6528/aaa48c

Abstract

Solar-driven photoelectrochemical (PEC) water splitting has attracted a great deal of attention recently. Silicon (Si) is an ideal light absorber for solar energy conversion. However, the poor stability and inefficient surface catalysis of Si photocathodes for the hydrogen evolution reaction (HER) have remained key challenges. Alternatively, MoS₂ has been reported to exhibit excellent catalysis performance if sufficient active sites for the HER are available. Here, ultrathin MoS₂ nanoflakes are directly synthesized to coat arrays of Ag-core Si-shell nanospheres (Ag@Si NSs) by using chemical vapor deposition. Due to the high surface area ratio and large curvature of these NSs, the as-grown MoS₂ nanoflakes can accommodate more active sites. In addition, the high-quality coating of MoS₂ nanoflakes on the Ag@Si NSs protects the photocathode from damage during the PEC reaction. An photocurrent density of 33.3 mA cm^-2 at a voltage of -0.4 V is obtained versus the reversible hydrogen electrode. The as-prepared nanostructure as a hydrogen photocathode is evidenced to have high stability over 12 h PEC performance. This work opens up opportunities for composite photocathodes with high activity and stability using cheap and stable co-catalysts.