Shining a Light on Solar Water Splitting

摘要

Direct photocatalytic splitting water to hydrogen and oxygen has been the subject of thousands of papers over the past four decades, with many optimistic promises. In his Perspective "A nickel finish protects silicon photoanodes for water splitting" (15 November 2013, p. 811), J. A. Turner highlights progress in finding a stable electrode. It's fascinating science, but could this actually be a successful technology? Although cells with vertical electrodes are usually used for laboratory work, large-scale deployment will require solar cells angled according to latitude. Let's set aside the gas separation and membrane issues required and focus on some simple but critically important questions that must be addressed if direct solar water splitting is to be an important contender. Quantum efficiency is not the only issue.