Photoelectrochemical (PEC) nitrogen reduction reaction (NRR), which produces ammonia under ambient conditions by combining the merits of electrocatalysis and photocatalysis, represents an attractive prospect for nitrogen fixation. Limited by the choice of suitable p-type semiconductor, PEC nitrogen fixation should be preferentially achieved by cathodic NRR integrated with photoanode rather than direct photocathodic NRR. Even in such an approach, it still remains elusive how to design catalytically active sites on the dark cathode toward high activity and selectivity in PEC NRR. Herein, we report a new strategy for tailoring cathodic bismuth (Bi) sites with boron (B) doping and rolling curvature. The B doping in Bi matrix greatly reduces the energy barrier of the potential-determining step of N₂ → *NNH in NRR while the high curvature surface on nanorolls facilitates the adsorption of N₂. The integration of B doping and rolling curvature in a single cathodic catalyst boosts PEC NRR performance when combined with TiO₂ nanorods array as photoanode to harvest light and provide photo-generated electrons. Such a PEC system offers an ammonia yield rate of 29.2 mg_NH3 g_cat.⁻¹ h⁻¹ and Faradaic efficiency of 8.3 % at a bias of 0.48 V versus RHE in nitrogen fixation. This work provides a guideline for the rational design of highly active and selective metallic catalyst in PEC NRR.

通过结合电催化和光催化的优点在环境条件下产生氨的光电化学（PEC）氮还原反应（NRR）代表了固氮的诱人前景。受制于合适的p型半导体的限制，PEC固氮应优先通过与光阳极集成的阴极NRR而非直接的光阴极NRR来实现。即使采用这种方法，如何设计暗阴极上的催化活性位以实现PEC NRR的高活性和选择性仍然是未知的。在这里，我们报告了一种新的策略，用于用硼（B）掺杂和滚动曲率定制阴极铋（Bi）位置。Bi矩阵中的B掺杂大大降低了N ₂势能确定步骤的能垒→* NNH中的NNH，而纳米辊上的高曲率表面则有助于N ₂的吸附。当与TiO ₂纳米棒阵列作为光阳极来收集光并提供光生电子时，B掺杂和滚动曲率在单个阴极催化剂中的集成可提高PEC NRR性能。这样的PEC系统提供的氨气产率为29.2 mg _NH3 g _cat。^-1  h ^-1和0.48 V偏压下的法拉第效率相对于RHE在固氮中的效率为8.3％。这项工作为合理设计PEC NRR中的高活性和选择性金属催化剂提供了指导。