Heterostructured Bi 2 S 3 /MoS 2 Nanoarrays for Efficient Electrocatalytic Nitrate Reduction to Ammonia Under Ambient Conditions.

Developing efficient electrocatalysts to realize the nitrate reduction reaction (eNO 3 - RR) for ammonia synthesis as an alternative to the traditional Haber-Bosch production process is of great significance. Herein, the heterostructured Bi 2 S 3 /MoS 2 nanoarrays were successfully synthesized by Bi 2 S 3 nanowires anchored on MoS 2 nanosheets. Owing to the interfacial coupling effect, both particular surface area and exposure active sites increase. Density functional theory further uncovered that the excellent activity originates from charge transfer of the interface and a low potential barrier of 0.58 eV for hydrogenation of *NO to *NOH on Bi 2 S 3 /MoS 2 . Compared with pure Bi 2 S 3 and MoS 2 catalysts, the heterostructured Bi 2 S 3 /MoS 2 nanoarrays exhibit a superior NH 3 yield of 15.04 × 10 -2 mmol·h -1 ·cm -2 and a Faraday efficiency of 88.4% at -0.8 V versus the reversible hydrogen electrode. This work provides a new avenue to explore advanced electrocatalysts, which is expected to shorten the distance from the practical application of the eNO 3 - RR technology.