Uji Pratomo

1 Introduction At present, rare earth elements (REEs) are an important and interesting topic, and receive considerable attention[1] because of their unique properties, high economic value, and being useful in various fields.[2] Some REEs are widely applied in conventional industrial fields such as metallurgy, ceramics, magnets, electronics, nuclear, and widely applied in advanced industries such as hybrid cars, cell phones, neon lights, and defense technology.[3,4] Due to its vast...

This is an early access version, the complete PDF, HTML, and XML versions will be available soon. Open AccessArticle by Uji Pratomo 1,2,*, Salmahaminati 3,4, Minori Abe 3,5, Masahiko Hada 3, Santhy Wyantuti 1, Husein H.

1. Introduction Water-splitting, which involves separating oxygen and hydrogen from water, is a fascinating approach to the renewable, environmentally friendly, non-polluting, and highly efficient production of hydrogen energy [1,2,3]. Compared to other methods, such as radiolysis [4], thermal decomposition [5], photobiological [6], and photocatalytic [7], photoelectrochemical or PEC is considered simple, cheap, and generates a high solar-to-hydrogen (STH) conversion efficiency [2,8,9].