Photoelectrochemical (PEC) splitting of water into hydrogen and oxygen is a promising way for the production of clean, and storable form of fuel but the PEC efficiency has remained low. Herein, we demonstrate enhanced light harvesting, charge carrier separation/transfer, and catalyst management with bifacial design for the Si-based photocathodes to achieve best-in-class hydrogen generation with excellent electrochemical stability. Decoupling the light harvesting side from the electrocatalytic surface nullifies parasitic light absorption and enables Si photocathodes that exhibit a photocurrent density of 39.01 mA/cm² and stability over 370 h in 1 M H₂SO₄(aq) electrolyte due to fully covered a 15 nm Pt without any intentional protective layer. Furthermore, the bifacial Si photocathode system with semi-transparent Pt layer of 5 nm developed herein are capable of collecting sunlight not only on the light harvesting side but also on the back side of the device, resulting in a photocurrent density of 61.20 mA/cm² under bifacial two-sun illumination, which yields 56.88% of excess hydrogen when compared to the monofacial PEC system. Combining the bifacial design with surface texturing and antireflection coating enables excellent omnidirectional light harvesting capability with a record hydrogen (photocurrent) generation, which provides a promising way to realize practical PEC water splitting applications.

将水分解成氢和氧的光电化学（PEC）是生产清洁，可存储形式的燃料的有前途的方法，但PEC效率一直很低。在本文中，我们通过双面设计针对Si基光电阴极展示了增强的光收集，电荷载流子分离/转移和催化剂管理功能，以实现一流的氢生成以及出色的电化学稳定性。将光收集侧与电催化表面解耦可使寄生光吸收无效，并使Si光电阴极在1 MH ₂ SO _4中的光电流密度为39.01 mA / cm ^2，并且在370 h内具有稳定性（aq）电解质，因为它完全覆盖了15 nm Pt，而没有任何故意的保护层。而且，本文开发的具有5nm的半透明Pt层的双面Si光电阴极系统不仅能够在器件的光收集侧而且在器件的背面上收集日光，从而导致光电流密度为61.20mA / cm。²在双面太阳光照射下比单面PEC系统产生56.88％的过量氢。将双面设计与表面纹理化和抗反射涂层相结合，可以实现出色的全向光收集能力以及创纪录的氢（光电流）生成，这为实现实际的PEC分水应用提供了一种有希望的方法。