Both 感情 (gǎnqíng) and 情感 (qínggǎn) are nouns that mean "emotion". Some examples:
这复杂的情感使埃拉想起了自己的丈夫。[src]
These complex emotions cause Ella to think of her own husband.最后这种感情再也抑制不了。[src]
Finally, these kinds of emotions [are] no longer inhibiting.
I can't see a difference. I found a Baidu Zhidao article which I translate below, which asserts there is a difference, but it didn't help me understand what the difference is. Ideally, it would be nice to have concrete examples which identify the difference.
Question: What examples highlight the difference between 感情 and 情感?
From 感情和情感有区别吗?
有区别。
There's a difference.
情感是态度这一整体中的一部分,它与态度中的内向感受、意向具有协调一致性,是态度在生理上一种较复杂而又稳定的生理评价和体验。情感包括道德感和价值感两个方面,具体表现为爱情、幸福、仇恨、厌恶、美感等等。
情感 is the entirety of 态度 ("attitude"), inside it and 态度 we feel and incline to have coordinated consistency. It's 态度 physiology's comparatively complicated and stable physiological evaluation and self-experience. 情感 includes feelings of virtue and value; concrete expressions of romance, happiness, hatred, loathing, sense of beauty, and so on.
而感情,是人内心的各种的感觉、思想和行为的一种综合的心理和生理状态,是对外界刺激所产生的心理反应,以及附带的生理反应。如:喜、怒、哀、乐等,感情是个人的主观体验和感受,常跟心情、气质、性格和性情有关。
While 感情, is a person's internal kind of 感情, thoughts and behaviors in a composite mental and physiological state. It's the external world which provokes and give rise to mental reaction, as well as incidental physiological reactions. For example, like, anger, sorry, happiness. 感情 is a personal subjective experience and sense, commonly related with mood, temperament, disposition, and nature.
In my mind, that's a lot of words, and very little clarity. (And it's also just "some random person on the Internet said so", which is unreliable.)