<p>Recovering ammonia (NH₃) from ammonium (NH₄⁺)-containing wastewater simultaneously achieves resource recovery and wastewater treatment. Given that NH₃ recovery involves a reversible NH₄⁺ hydrolysis reaction, traditional strategy requires alkaline reactants for promoting the reaction forward and energy-intensive heating for recovering NH₃, resulting in substantial cost and energy consumption. Here we propose a solar-driven NH₃ recovery strategy enabled by floatable amino-grafted (‒NH₂) MXene (Ti₃C₂)-based sponge that possesses local alkaline environment and interfacial heat on water surface. Both H⁺ trapping via ‒NH₂ groups and NH₃ evaporating via interfacial solar heating thermodynamically facilitate efficient and sustainable NH₃ recovery. Taking ammonia chloride (NH₄Cl) wastewater for example, a NH₃ recovery rate of 0.6 mol m⁻² h⁻¹ with a purity of 99.8% is obtained under 5 sun without extra reagents and energy consumption, and the recovered NH₃ can be directly used as nitrogen fertilizer. Besides, the amino-grafted MXene-based sponge is also capable of being fully regenerated to its initial performance under 15 sun, and hydrochloric acid, a valuable by-product, can be obtained during this process. Life-cycle and techno-economic assessments highlight the advantages of solar-driven NH₃ recovery in terms of environmental benefits and economic potential.</p>