 photosystem 
 ii ( psii ) offers a biological and sustainable route 
 of photochemical water oxidation to o2 and can provide 
 protons and electrons for the generation of solar fuels , such as h2 . 
 we present a rational strategy to electrostatically improve 
 the orientation of psii from a thermophilic cyanobacterium , thermosynechococcus elongatus , on a nanostructured 
 indium tin oxide ( ito ) electrode and to covalently immobilize psii 
 on the electrode . 
 the ito electrode was modified with a self - assembled 
 monolayer ( sam ) of phosphonic acid ito linkers with a dangling carboxylate 
 moiety . 
 the negatively charged carboxylate attracts the positive dipole 
 on the electron acceptor side of psii via coulomb interactions . 
 covalent 
 attachment of psii in its electrostatically improved orientation to 
 the sam - modified ito electrode was accomplished via an amide bond 
 to further enhance red - light - driven , direct electron transfer and 
 stability of the psii hybrid photoelectrode . 
Supplementary Material